LTD Puzzle 19: Take numbers between 1 and 100

[SQLDenis]

Take numbers between 1 and 100 and do the following

if the number is a prime mark it
if the number is divisible by 5 mark it
if the number is divisible by 7 mark it
if the number is divisible by 7 and 5 mark it

result would be something like this

number	Prime	div by 5	div by 7	div by 5 and 7
1	no	no	no	no
2	yes	no	no	no
..	..	..	..	..
..	..	..	..	..
..	..	..	..	..
35	no	yes	yes	yes
..	..	..	..	..
..	..	..	..	..
..	..	..	..	..
100	no	yes	no	no

you can choose any language you want

[SQLDenis]

Here is my solution in Transact SQL

tsqlLine number Off | Show | Select all

1. SELECT number, CASE WHEN
2. number = 1
3. OR number % 2 = 0 and number > 2
4. OR number % 3 = 0 and number > 3
5. OR number % 5 = 0 and number > 5
6. OR number % 7 = 0 and number > 7 THEN 'NO' ELSE 'YES' END AS IsPrime,
7. CASE WHEN number % 5 = 0 THEN 'Yes' ELSE 'No' END AS [div BY 5] ,
8.  CASE WHEN number % 7 = 0  THEN 'Yes' ELSE 'No' END AS [div BY 7],
9. CASE WHEN number % 5 = 0 and number % 7 = 0  THEN 'Yes' ELSE 'No' END AS [div BY 5 and 7]
10.  FROM master..spt_values
11. WHERE type = 'P'
12. and number between 1 and 100

Code is hidden, SHOW

[rizzo]

Here's the fastest answer i can give in VB .Net.
Would normally complete puzzles in C#, but i felt like doing one in VB .Net as it is my first language, and i can't neglect the poor thing

vbnetLine number Off | Show | Select all

1. Module Module1
2.  
3.     Sub Main()
4.         Dim sTicks As Long = DateTime.Now.Ticks
5.         Dim output As String = ""
6.         output &= "+------+-----+--------+--------+--------------+" & vbCrLf & _
7.                   "|Number|Prime|Div By 5|Div By 7|Div By 5 And 7|" & vbCrLf & _
8.                   "+------+-----+--------+--------+--------------+" & vbCrLf
9.         Dim db5, db7 As Boolean
10.         For i As Integer = 1 To 100
11.             db5 = False
12.             db7 = False
13.  
14.             output &= "|" & i.ToString.PadRight(6) & _
15.                       "|" & IIf(IsPrime(i), "yes  ", "no   ")
16.  
17.             If i >= 10 Then
18.                 If i Mod 5 = 0 Then db5 = True
19.                 If i >= 14 Then
20.                     If i Mod 7 = 0 Then db7 = True
21.                 End If
22.             End If
23.  
24.             output &= IIf(db5, "|yes     ", "|no      ") & IIf(db7, "|yes     ", "|no      ") & _
25.                       IIf(db5 And db7, "|yes           |", "|no            |") & vbCrLf
26.  
27.             output &= "+------+-----+--------+--------+--------------+" & vbCrLf
28.         Next
29.         Console.WriteLine("Calculated in {0} milliseconds", ((DateTime.Now.Ticks - sTicks) / 10000))
30.         Console.Write(output)
31.     End Sub
32.  
33.     Private Function IsPrime(ByVal i As Integer) As Boolean
34.         If i = 1 Then Return False
35.         For n As Integer = 2 To i - 1
36.             If i Mod n = 0 Then Return False
37.         Next
38.         Return True
39.     End Function
40. End Module
41.  

Code is hidden, SHOW

This produced the following result on my computer.
(which looks much sexier in the console window! )
Seems I underestimated the forum, which does print the output in a lovely system font.
nice one! =D

textLine number Off | Show | Select all

1. Calculated in 20.0288 milliseconds
2. +------+-----+--------+--------+--------------+
3. |Number|Prime|Div By 5|Div By 7|Div By 5 And 7|
4. +------+-----+--------+--------+--------------+
5. |1     |no   |no      |no      |no            |
6. +------+-----+--------+--------+--------------+
7. |2     |yes  |no      |no      |no            |
8. +------+-----+--------+--------+--------------+
9. |3     |yes  |no      |no      |no            |
10. +------+-----+--------+--------+--------------+
11. |4     |no   |no      |no      |no            |
12. +------+-----+--------+--------+--------------+
13. |5     |yes  |no      |no      |no            |
14. +------+-----+--------+--------+--------------+
15. |6     |no   |no      |no      |no            |
16. +------+-----+--------+--------+--------------+
17. |7     |yes  |no      |no      |no            |
18. +------+-----+--------+--------+--------------+
19. |8     |no   |no      |no      |no            |
20. +------+-----+--------+--------+--------------+
21. |9     |no   |no      |no      |no            |
22. +------+-----+--------+--------+--------------+
23. |10    |no   |yes     |no      |no            |
24. +------+-----+--------+--------+--------------+
25. |11    |yes  |no      |no      |no            |
26. +------+-----+--------+--------+--------------+
27. |12    |no   |no      |no      |no            |
28. +------+-----+--------+--------+--------------+
29. |13    |yes  |no      |no      |no            |
30. +------+-----+--------+--------+--------------+
31. |14    |no   |no      |yes     |no            |
32. +------+-----+--------+--------+--------------+
33. |15    |no   |yes     |no      |no            |
34. +------+-----+--------+--------+--------------+
35. |16    |no   |no      |no      |no            |
36. +------+-----+--------+--------+--------------+
37. |17    |yes  |no      |no      |no            |
38. +------+-----+--------+--------+--------------+
39. |18    |no   |no      |no      |no            |
40. +------+-----+--------+--------+--------------+
41. |19    |yes  |no      |no      |no            |
42. +------+-----+--------+--------+--------------+
43. |20    |no   |yes     |no      |no            |
44. +------+-----+--------+--------+--------------+
45. |21    |no   |no      |yes     |no            |
46. +------+-----+--------+--------+--------------+
47. |22    |no   |no      |no      |no            |
48. +------+-----+--------+--------+--------------+
49. |23    |yes  |no      |no      |no            |
50. +------+-----+--------+--------+--------------+
51. |24    |no   |no      |no      |no            |
52. +------+-----+--------+--------+--------------+
53. |25    |no   |yes     |no      |no            |
54. +------+-----+--------+--------+--------------+
55. |26    |no   |no      |no      |no            |
56. +------+-----+--------+--------+--------------+
57. |27    |no   |no      |no      |no            |
58. +------+-----+--------+--------+--------------+
59. |28    |no   |no      |yes     |no            |
60. +------+-----+--------+--------+--------------+
61. |29    |yes  |no      |no      |no            |
62. +------+-----+--------+--------+--------------+
63. |30    |no   |yes     |no      |no            |
64. +------+-----+--------+--------+--------------+
65. |31    |yes  |no      |no      |no            |
66. +------+-----+--------+--------+--------------+
67. |32    |no   |no      |no      |no            |
68. +------+-----+--------+--------+--------------+
69. |33    |no   |no      |no      |no            |
70. +------+-----+--------+--------+--------------+
71. |34    |no   |no      |no      |no            |
72. +------+-----+--------+--------+--------------+
73. |35    |no   |yes     |yes     |yes           |
74. +------+-----+--------+--------+--------------+
75. |36    |no   |no      |no      |no            |
76. +------+-----+--------+--------+--------------+
77. |37    |yes  |no      |no      |no            |
78. +------+-----+--------+--------+--------------+
79. |38    |no   |no      |no      |no            |
80. +------+-----+--------+--------+--------------+
81. |39    |no   |no      |no      |no            |
82. +------+-----+--------+--------+--------------+
83. |40    |no   |yes     |no      |no            |
84. +------+-----+--------+--------+--------------+
85. |41    |yes  |no      |no      |no            |
86. +------+-----+--------+--------+--------------+
87. |42    |no   |no      |yes     |no            |
88. +------+-----+--------+--------+--------------+
89. |43    |yes  |no      |no      |no            |
90. +------+-----+--------+--------+--------------+
91. |44    |no   |no      |no      |no            |
92. +------+-----+--------+--------+--------------+
93. |45    |no   |yes     |no      |no            |
94. +------+-----+--------+--------+--------------+
95. |46    |no   |no      |no      |no            |
96. +------+-----+--------+--------+--------------+
97. |47    |yes  |no      |no      |no            |
98. +------+-----+--------+--------+--------------+
99. |48    |no   |no      |no      |no            |
100. +------+-----+--------+--------+--------------+
101. |49    |no   |no      |yes     |no            |
102. +------+-----+--------+--------+--------------+
103. |50    |no   |yes     |no      |no            |
104. +------+-----+--------+--------+--------------+
105. |51    |no   |no      |no      |no            |
106. +------+-----+--------+--------+--------------+
107. |52    |no   |no      |no      |no            |
108. +------+-----+--------+--------+--------------+
109. |53    |yes  |no      |no      |no            |
110. +------+-----+--------+--------+--------------+
111. |54    |no   |no      |no      |no            |
112. +------+-----+--------+--------+--------------+
113. |55    |no   |yes     |no      |no            |
114. +------+-----+--------+--------+--------------+
115. |56    |no   |no      |yes     |no            |
116. +------+-----+--------+--------+--------------+
117. |57    |no   |no      |no      |no            |
118. +------+-----+--------+--------+--------------+
119. |58    |no   |no      |no      |no            |
120. +------+-----+--------+--------+--------------+
121. |59    |yes  |no      |no      |no            |
122. +------+-----+--------+--------+--------------+
123. |60    |no   |yes     |no      |no            |
124. +------+-----+--------+--------+--------------+
125. |61    |yes  |no      |no      |no            |
126. +------+-----+--------+--------+--------------+
127. |62    |no   |no      |no      |no            |
128. +------+-----+--------+--------+--------------+
129. |63    |no   |no      |yes     |no            |
130. +------+-----+--------+--------+--------------+
131. |64    |no   |no      |no      |no            |
132. +------+-----+--------+--------+--------------+
133. |65    |no   |yes     |no      |no            |
134. +------+-----+--------+--------+--------------+
135. |66    |no   |no      |no      |no            |
136. +------+-----+--------+--------+--------------+
137. |67    |yes  |no      |no      |no            |
138. +------+-----+--------+--------+--------------+
139. |68    |no   |no      |no      |no            |
140. +------+-----+--------+--------+--------------+
141. |69    |no   |no      |no      |no            |
142. +------+-----+--------+--------+--------------+
143. |70    |no   |yes     |yes     |yes           |
144. +------+-----+--------+--------+--------------+
145. |71    |yes  |no      |no      |no            |
146. +------+-----+--------+--------+--------------+
147. |72    |no   |no      |no      |no            |
148. +------+-----+--------+--------+--------------+
149. |73    |yes  |no      |no      |no            |
150. +------+-----+--------+--------+--------------+
151. |74    |no   |no      |no      |no            |
152. +------+-----+--------+--------+--------------+
153. |75    |no   |yes     |no      |no            |
154. +------+-----+--------+--------+--------------+
155. |76    |no   |no      |no      |no            |
156. +------+-----+--------+--------+--------------+
157. |77    |no   |no      |yes     |no            |
158. +------+-----+--------+--------+--------------+
159. |78    |no   |no      |no      |no            |
160. +------+-----+--------+--------+--------------+
161. |79    |yes  |no      |no      |no            |
162. +------+-----+--------+--------+--------------+
163. |80    |no   |yes     |no      |no            |
164. +------+-----+--------+--------+--------------+
165. |81    |no   |no      |no      |no            |
166. +------+-----+--------+--------+--------------+
167. |82    |no   |no      |no      |no            |
168. +------+-----+--------+--------+--------------+
169. |83    |yes  |no      |no      |no            |
170. +------+-----+--------+--------+--------------+
171. |84    |no   |no      |yes     |no            |
172. +------+-----+--------+--------+--------------+
173. |85    |no   |yes     |no      |no            |
174. +------+-----+--------+--------+--------------+
175. |86    |no   |no      |no      |no            |
176. +------+-----+--------+--------+--------------+
177. |87    |no   |no      |no      |no            |
178. +------+-----+--------+--------+--------------+
179. |88    |no   |no      |no      |no            |
180. +------+-----+--------+--------+--------------+
181. |89    |yes  |no      |no      |no            |
182. +------+-----+--------+--------+--------------+
183. |90    |no   |yes     |no      |no            |
184. +------+-----+--------+--------+--------------+
185. |91    |no   |no      |yes     |no            |
186. +------+-----+--------+--------+--------------+
187. |92    |no   |no      |no      |no            |
188. +------+-----+--------+--------+--------------+
189. |93    |no   |no      |no      |no            |
190. +------+-----+--------+--------+--------------+
191. |94    |no   |no      |no      |no            |
192. +------+-----+--------+--------+--------------+
193. |95    |no   |yes     |no      |no            |
194. +------+-----+--------+--------+--------------+
195. |96    |no   |no      |no      |no            |
196. +------+-----+--------+--------+--------------+
197. |97    |yes  |no      |no      |no            |
198. +------+-----+--------+--------+--------------+
199. |98    |no   |no      |yes     |no            |
200. +------+-----+--------+--------+--------------+
201. |99    |no   |no      |no      |no            |
202. +------+-----+--------+--------+--------------+
203. |100   |no   |yes     |no      |no            |
204. +------+-----+--------+--------+--------------+
205.  

Code is hidden, SHOW

[gmmastros]

Rizzo,

Check your results again. 5 is divisible 5, right?

[rizzo]

d'oh! Well spotted gmmastros. Here's the edit:

vbnetLine number Off | Show | Select all

1. Module Module1
2.  
3.     Sub Main()
4.         Dim sTicks As Long = DateTime.Now.Ticks
5.         Dim output As String = ""
6.         output &= "+------+-----+--------+--------+--------------+" & vbCrLf & _
7.                   "|Number|Prime|Div By 5|Div By 7|Div By 5 And 7|" & vbCrLf & _
8.                   "+------+-----+--------+--------+--------------+" & vbCrLf
9.         Dim db5, db7 As Boolean
10.         For i As Integer = 1 To 100
11.             db5 = False
12.             db7 = False
13.  
14.             output &= "|" & i.ToString.PadRight(6) & _
15.                       "|" & IIf(IsPrime(i), "yes  ", "no   ")
16.  
17.             If i >= 5 Then
18.                 If i Mod 5 = 0 Then db5 = True
19.                 If i >= 7 Then
20.                     If i Mod 7 = 0 Then db7 = True
21.                 End If
22.             End If
23.  
24.             output &= IIf(db5, "|yes     ", "|no      ") & IIf(db7, "|yes     ", "|no      ") & _
25.                       IIf(db5 And db7, "|yes           |", "|no            |") & vbCrLf
26.  
27.             output &= "+------+-----+--------+--------+--------------+" & vbCrLf
28.         Next
29.         Console.WriteLine("Calculated in {0} milliseconds", ((DateTime.Now.Ticks - sTicks) / 10000))
30.         Console.Write(output)
31.     End Sub
32.  
33.     Private Function IsPrime(ByVal i As Integer) As Boolean
34.         If i = 1 Then Return False
35.         For n As Integer = 2 To i - 1
36.             If i Mod n = 0 Then Return False
37.         Next
38.         Return True
39.     End Function
40. End Module
41.  

Code is hidden, SHOW

And the new result. I lost 10 milliseconds! But at least it's not completely wrong now!

textLine number Off | Show | Select all

1. Calculated in 30.0432 milliseconds
2. +------+-----+--------+--------+--------------+
3. |Number|Prime|Div By 5|Div By 7|Div By 5 And 7|
4. +------+-----+--------+--------+--------------+
5. |1     |no   |no      |no      |no            |
6. +------+-----+--------+--------+--------------+
7. |2     |yes  |no      |no      |no            |
8. +------+-----+--------+--------+--------------+
9. |3     |yes  |no      |no      |no            |
10. +------+-----+--------+--------+--------------+
11. |4     |no   |no      |no      |no            |
12. +------+-----+--------+--------+--------------+
13. |5     |yes  |yes     |no      |no            |
14. +------+-----+--------+--------+--------------+
15. |6     |no   |no      |no      |no            |
16. +------+-----+--------+--------+--------------+
17. |7     |yes  |no      |yes     |no            |
18. +------+-----+--------+--------+--------------+
19. |8     |no   |no      |no      |no            |
20. +------+-----+--------+--------+--------------+
21. |9     |no   |no      |no      |no            |
22. +------+-----+--------+--------+--------------+
23. |10    |no   |yes     |no      |no            |
24. +------+-----+--------+--------+--------------+
25. |11    |yes  |no      |no      |no            |
26. +------+-----+--------+--------+--------------+
27. |12    |no   |no      |no      |no            |
28. +------+-----+--------+--------+--------------+
29. |13    |yes  |no      |no      |no            |
30. +------+-----+--------+--------+--------------+
31. |14    |no   |no      |yes     |no            |
32. +------+-----+--------+--------+--------------+
33. |15    |no   |yes     |no      |no            |
34. +------+-----+--------+--------+--------------+
35. |16    |no   |no      |no      |no            |
36. +------+-----+--------+--------+--------------+
37. |17    |yes  |no      |no      |no            |
38. +------+-----+--------+--------+--------------+
39. |18    |no   |no      |no      |no            |
40. +------+-----+--------+--------+--------------+
41. |19    |yes  |no      |no      |no            |
42. +------+-----+--------+--------+--------------+
43. |20    |no   |yes     |no      |no            |
44. +------+-----+--------+--------+--------------+
45. |21    |no   |no      |yes     |no            |
46. +------+-----+--------+--------+--------------+
47. |22    |no   |no      |no      |no            |
48. +------+-----+--------+--------+--------------+
49. |23    |yes  |no      |no      |no            |
50. +------+-----+--------+--------+--------------+
51. |24    |no   |no      |no      |no            |
52. +------+-----+--------+--------+--------------+
53. |25    |no   |yes     |no      |no            |
54. +------+-----+--------+--------+--------------+
55. |26    |no   |no      |no      |no            |
56. +------+-----+--------+--------+--------------+
57. |27    |no   |no      |no      |no            |
58. +------+-----+--------+--------+--------------+
59. |28    |no   |no      |yes     |no            |
60. +------+-----+--------+--------+--------------+
61. |29    |yes  |no      |no      |no            |
62. +------+-----+--------+--------+--------------+
63. |30    |no   |yes     |no      |no            |
64. +------+-----+--------+--------+--------------+
65. |31    |yes  |no      |no      |no            |
66. +------+-----+--------+--------+--------------+
67. |32    |no   |no      |no      |no            |
68. +------+-----+--------+--------+--------------+
69. |33    |no   |no      |no      |no            |
70. +------+-----+--------+--------+--------------+
71. |34    |no   |no      |no      |no            |
72. +------+-----+--------+--------+--------------+
73. |35    |no   |yes     |yes     |yes           |
74. +------+-----+--------+--------+--------------+
75. |36    |no   |no      |no      |no            |
76. +------+-----+--------+--------+--------------+
77. |37    |yes  |no      |no      |no            |
78. +------+-----+--------+--------+--------------+
79. |38    |no   |no      |no      |no            |
80. +------+-----+--------+--------+--------------+
81. |39    |no   |no      |no      |no            |
82. +------+-----+--------+--------+--------------+
83. |40    |no   |yes     |no      |no            |
84. +------+-----+--------+--------+--------------+
85. |41    |yes  |no      |no      |no            |
86. +------+-----+--------+--------+--------------+
87. |42    |no   |no      |yes     |no            |
88. +------+-----+--------+--------+--------------+
89. |43    |yes  |no      |no      |no            |
90. +------+-----+--------+--------+--------------+
91. |44    |no   |no      |no      |no            |
92. +------+-----+--------+--------+--------------+
93. |45    |no   |yes     |no      |no            |
94. +------+-----+--------+--------+--------------+
95. |46    |no   |no      |no      |no            |
96. +------+-----+--------+--------+--------------+
97. |47    |yes  |no      |no      |no            |
98. +------+-----+--------+--------+--------------+
99. |48    |no   |no      |no      |no            |
100. +------+-----+--------+--------+--------------+
101. |49    |no   |no      |yes     |no            |
102. +------+-----+--------+--------+--------------+
103. |50    |no   |yes     |no      |no            |
104. +------+-----+--------+--------+--------------+
105. |51    |no   |no      |no      |no            |
106. +------+-----+--------+--------+--------------+
107. |52    |no   |no      |no      |no            |
108. +------+-----+--------+--------+--------------+
109. |53    |yes  |no      |no      |no            |
110. +------+-----+--------+--------+--------------+
111. |54    |no   |no      |no      |no            |
112. +------+-----+--------+--------+--------------+
113. |55    |no   |yes     |no      |no            |
114. +------+-----+--------+--------+--------------+
115. |56    |no   |no      |yes     |no            |
116. +------+-----+--------+--------+--------------+
117. |57    |no   |no      |no      |no            |
118. +------+-----+--------+--------+--------------+
119. |58    |no   |no      |no      |no            |
120. +------+-----+--------+--------+--------------+
121. |59    |yes  |no      |no      |no            |
122. +------+-----+--------+--------+--------------+
123. |60    |no   |yes     |no      |no            |
124. +------+-----+--------+--------+--------------+
125. |61    |yes  |no      |no      |no            |
126. +------+-----+--------+--------+--------------+
127. |62    |no   |no      |no      |no            |
128. +------+-----+--------+--------+--------------+
129. |63    |no   |no      |yes     |no            |
130. +------+-----+--------+--------+--------------+
131. |64    |no   |no      |no      |no            |
132. +------+-----+--------+--------+--------------+
133. |65    |no   |yes     |no      |no            |
134. +------+-----+--------+--------+--------------+
135. |66    |no   |no      |no      |no            |
136. +------+-----+--------+--------+--------------+
137. |67    |yes  |no      |no      |no            |
138. +------+-----+--------+--------+--------------+
139. |68    |no   |no      |no      |no            |
140. +------+-----+--------+--------+--------------+
141. |69    |no   |no      |no      |no            |
142. +------+-----+--------+--------+--------------+
143. |70    |no   |yes     |yes     |yes           |
144. +------+-----+--------+--------+--------------+
145. |71    |yes  |no      |no      |no            |
146. +------+-----+--------+--------+--------------+
147. |72    |no   |no      |no      |no            |
148. +------+-----+--------+--------+--------------+
149. |73    |yes  |no      |no      |no            |
150. +------+-----+--------+--------+--------------+
151. |74    |no   |no      |no      |no            |
152. +------+-----+--------+--------+--------------+
153. |75    |no   |yes     |no      |no            |
154. +------+-----+--------+--------+--------------+
155. |76    |no   |no      |no      |no            |
156. +------+-----+--------+--------+--------------+
157. |77    |no   |no      |yes     |no            |
158. +------+-----+--------+--------+--------------+
159. |78    |no   |no      |no      |no            |
160. +------+-----+--------+--------+--------------+
161. |79    |yes  |no      |no      |no            |
162. +------+-----+--------+--------+--------------+
163. |80    |no   |yes     |no      |no            |
164. +------+-----+--------+--------+--------------+
165. |81    |no   |no      |no      |no            |
166. +------+-----+--------+--------+--------------+
167. |82    |no   |no      |no      |no            |
168. +------+-----+--------+--------+--------------+
169. |83    |yes  |no      |no      |no            |
170. +------+-----+--------+--------+--------------+
171. |84    |no   |no      |yes     |no            |
172. +------+-----+--------+--------+--------------+
173. |85    |no   |yes     |no      |no            |
174. +------+-----+--------+--------+--------------+
175. |86    |no   |no      |no      |no            |
176. +------+-----+--------+--------+--------------+
177. |87    |no   |no      |no      |no            |
178. +------+-----+--------+--------+--------------+
179. |88    |no   |no      |no      |no            |
180. +------+-----+--------+--------+--------------+
181. |89    |yes  |no      |no      |no            |
182. +------+-----+--------+--------+--------------+
183. |90    |no   |yes     |no      |no            |
184. +------+-----+--------+--------+--------------+
185. |91    |no   |no      |yes     |no            |
186. +------+-----+--------+--------+--------------+
187. |92    |no   |no      |no      |no            |
188. +------+-----+--------+--------+--------------+
189. |93    |no   |no      |no      |no            |
190. +------+-----+--------+--------+--------------+
191. |94    |no   |no      |no      |no            |
192. +------+-----+--------+--------+--------------+
193. |95    |no   |yes     |no      |no            |
194. +------+-----+--------+--------+--------------+
195. |96    |no   |no      |no      |no            |
196. +------+-----+--------+--------+--------------+
197. |97    |yes  |no      |no      |no            |
198. +------+-----+--------+--------+--------------+
199. |98    |no   |no      |yes     |no            |
200. +------+-----+--------+--------+--------------+
201. |99    |no   |no      |no      |no            |
202. +------+-----+--------+--------+--------------+
203. |100   |no   |yes     |no      |no            |
204. +------+-----+--------+--------+--------------+
205.  

Code is hidden, SHOW

[gmmastros]

My version, in vb6:

To run this code, create a project with a single form. There should be a button and a textbox (named txtOutput) configured for multi-line.

vbLine number Off | Show | Select all

1. Option Explicit
2.  
3. Private Sub Command1_Click()
4.    
5.     Dim i As Long
6.     Dim arOutput(1 To 10000) As String
7.     Dim Start As Single
8.    
9.     Start = Timer
10.     For i = 1 To 10000
11.    
12.         arOutput(i) = CStr(i) & vbTab & _
13.                       IIf(IsPrime(i), "Yes", "No") & vbTab & _
14.                       IIf(i Mod 5 = 0, "Yes", "No") & vbTab & _
15.                       IIf(i Mod 7 = 0, "Yes", "No") & vbTab & _
16.                       IIf(i Mod 35 = 0, "Yes", "No")
17.    
18.     Next
19.    
20.     txtOutput.Text = Join(arOutput, vbCrLf)
21.    
22.     MsgBox Format((Timer - Start) * 1000, "0.000") & " milliseconds"
23.    
24. End Sub
25.  
26. Private Function IsPrime(ByVal Number As Long) As Boolean
27.    
28.     Dim i As Long
29.    
30.     If Number = 1 Then
31.         IsPrime = False
32.         Exit Function
33.     End If
34.    
35.     IsPrime = True
36.    
37.     For i = 2 To Sqr(Number)
38.         If Number Mod i = 0 Then
39.             IsPrime = False
40.             Exit For
41.         End If
42.     Next
43.    
44. End Function
45.  

Code is hidden, SHOW

With values 1 to 100, this runs so fast that it's claiming 0 milliseconds. If I change this to 1 to 10,000, it runs in 62 milli-seconds on my computer.

[rizzo]

Ah, very nice gmmastros ^^
I think i should remove my < tests. They're just creating more work than they're saving now that it's only < 5 lol.

I'll probably repost this one in a different language later.

[gmmastros]

Rizzo,

One of the reasons why I enjoy these puzzles is because I don't have an opportunity to have my code reviewed by my peers. I bet there are a lot of programmers in a similar situation. I've created a similar solution in vb2008, and it executes even faster. With numbers from 1 to 10,000 it executes in 12 milliseconds (4 or 5 times faster than the VB6 version). If you'd like, I'd be willing to share my thoughts with you on how you can speed up your code.

[rizzo]

Constructive criticism is always welcome

[gmmastros]

Ok.

I'll put my comments in the hide box so it won't affect the code that others may write.

textLine number Off | Show | Select all

1. In your IsPrime function, your loop can stop at the square root of the number you are testing.  This makes the loop considerably shorter.  While this is an interesting observation, it's not the biggest contributor to the performance issues, and it doesn't really have a 'real world' use because it is dependent on the nature of prime numbers.  It does translate in to real world programming in the sense that reducing the number of loops in your code has an impact on performance.
2.  
3. More importantly, from a performance perspective, is the way you are handling strings.  Your code is building up one monster string that you eventually output to the console.  If you take a close look at my VB6 solution, you will see that I create an array to store each line of the output.  Since each line is small, the string concatenation will be super fast.  Once strings start to get bigger, they tend to slow down.  By creating a string array, each element in it is very short.  At the end, I join the array and output it to a text box.
4.  
5. I'm not very familiar with vb.net, but I know there is a string builder class that you can use.  I understand that string builder is much faster at handling large strings.  I don't know which would be faster, string builder vs. array.
6.  
7. The string issue accounts for most of the performance improvements, but there are other minor issues, like declaring variables, assigning a value to it, and then using it.  I mean... sometimes it's necessary to use variables (obviously), but there are some speed improvements that can be made by reducing their use.
8.  
9. Instead of...
10.  
11. If i Mod 5 = 0 Then db5 = True
12. ...
13. IIf(db5, "|yes     ", "|no      ")
14.  
15. You could do...
16.  
17. iif(i mod 5 = 0, "|yes     ", "|no      ")
18.  
19. This won't make a huge difference, but with bigger loops, it can make a difference.  In vb.net, it's possible that the compiler will 'compile this out'.  I'm not sure.

Code is hidden, SHOW

[rizzo]

Thanks for the feedback.

I used a large string because i found that the Console.WriteLine was taking the bulk of time to execute and a single large call took much less time than multiple small ones. I'll try it with an array definately.

With the db5 and db7 booleans, i figured that if i set these to true or false, i can simply test the boolean values when it comes to building the string. This means i only do two modulus calculation, rather than four (/5, /7, /5 & /7).
Is there no performance penalty to performing the modulus twice more compared to storing the result of the modulus as booleans and then testing the booleans?

Thanks again for the feedback ^_^

[gmmastros]

Thanks for the feedback.
With the db5 and db7 booleans, i figured that if i set these to true or false, i can simply test the boolean values when it comes to building the string. This means i only do two modulus calculation, rather than four (/5, /7, /5 & /7).
Is there no performance penalty to performing the modulus twice more compared to storing the result of the modulus as booleans and then testing the booleans?

I don't know. You'd have to test that. I do know that if a number is divisible by 5 and 7, it's also divisible by 35, so you can just test for that. You'd probably have to increase the loop to 1,000,000 to test the timing of it though. Mod division is very fast to begin with.

[rizzo]

Thanks for the advice gmmastros. Got it running at 0ms on 100 entries.
It spiradically takes 10ms or 0ms to do 1000 but i think that's processor task switching or it would always take 10ms.

The new code is:

vbnetLine number Off | Show | Select all

1. The Mod 35 and square root tricks saved loads of time. Also took out the lines between entries.
2.  
3. Module Module1
4.     Sub Main()
5.         Dim sTicks As Long = DateTime.Now.Ticks
6.         Dim output As New System.Collections.Generic.List(Of String)
7.         output.Add("+------+-----+--------+--------+--------------+" & vbCrLf & _
8.                    "|Number|Prime|Div By 5|Div By 7|Div By 5 And 7|" & vbCrLf & _
9.                    "+------+-----+--------+--------+--------------+")
10.         For i As Integer = 1 To 100
11.             Dim s As String = ""
12.             s &= "|" & i.ToString.PadRight(6) & _
13.                  IIf(IsPrime(i), "|yes  ", "|no   ")
14.             s &= IIf(i Mod 5 = 0, "|yes     ", "|no      ") & _
15.                  IIf(i Mod 7 = 0, "|yes     ", "|no      ") & _
16.                  IIf(i Mod 35 = 0, "|yes           |", "|no            |")
17.             output.Add(s)
18.         Next
19.         output.Add("+------+-----+--------+--------+--------------+")
20.         Dim tTime As Decimal = CDec((DateTime.Now.Ticks - sTicks) / 10000)
21.         Console.WriteLine(String.Join(vbCrLf, output.ToArray()))
22.         Console.WriteLine("Calculated in {0} milliseconds", tTime)
23.     End Sub
24.  
25.     Private Function IsPrime(ByVal i As Integer) As Boolean
26.         If i = 1 Then Return False
27.         For n As Integer = 2 To Math.Sqrt(i)
28.             If i Mod n = 0 Then Return False
29.         Next
30.         Return True
31.     End Function
32. End Module
33.  

Code is hidden, SHOW

And the new output is:

textLine number Off | Show | Select all

1. +------+-----+--------+--------+--------------+
2. |Number|Prime|Div By 5|Div By 7|Div By 5 And 7|
3. +------+-----+--------+--------+--------------+
4. |1     |no   |no      |no      |no            |
5. |2     |yes  |no      |no      |no            |
6. |3     |yes  |no      |no      |no            |
7. |4     |no   |no      |no      |no            |
8. |5     |yes  |yes     |no      |no            |
9. |6     |no   |no      |no      |no            |
10. |7     |yes  |no      |yes     |no            |
11. |8     |no   |no      |no      |no            |
12. |9     |no   |no      |no      |no            |
13. |10    |no   |yes     |no      |no            |
14. |11    |yes  |no      |no      |no            |
15. |12    |no   |no      |no      |no            |
16. |13    |yes  |no      |no      |no            |
17. |14    |no   |no      |yes     |no            |
18. |15    |no   |yes     |no      |no            |
19. |16    |no   |no      |no      |no            |
20. |17    |yes  |no      |no      |no            |
21. |18    |no   |no      |no      |no            |
22. |19    |yes  |no      |no      |no            |
23. |20    |no   |yes     |no      |no            |
24. |21    |no   |no      |yes     |no            |
25. |22    |no   |no      |no      |no            |
26. |23    |yes  |no      |no      |no            |
27. |24    |no   |no      |no      |no            |
28. |25    |no   |yes     |no      |no            |
29. |26    |no   |no      |no      |no            |
30. |27    |no   |no      |no      |no            |
31. |28    |no   |no      |yes     |no            |
32. |29    |yes  |no      |no      |no            |
33. |30    |no   |yes     |no      |no            |
34. |31    |yes  |no      |no      |no            |
35. |32    |no   |no      |no      |no            |
36. |33    |no   |no      |no      |no            |
37. |34    |no   |no      |no      |no            |
38. |35    |no   |yes     |yes     |yes           |
39. |36    |no   |no      |no      |no            |
40. |37    |yes  |no      |no      |no            |
41. |38    |no   |no      |no      |no            |
42. |39    |no   |no      |no      |no            |
43. |40    |no   |yes     |no      |no            |
44. |41    |yes  |no      |no      |no            |
45. |42    |no   |no      |yes     |no            |
46. |43    |yes  |no      |no      |no            |
47. |44    |no   |no      |no      |no            |
48. |45    |no   |yes     |no      |no            |
49. |46    |no   |no      |no      |no            |
50. |47    |yes  |no      |no      |no            |
51. |48    |no   |no      |no      |no            |
52. |49    |no   |no      |yes     |no            |
53. |50    |no   |yes     |no      |no            |
54. |51    |no   |no      |no      |no            |
55. |52    |no   |no      |no      |no            |
56. |53    |yes  |no      |no      |no            |
57. |54    |no   |no      |no      |no            |
58. |55    |no   |yes     |no      |no            |
59. |56    |no   |no      |yes     |no            |
60. |57    |no   |no      |no      |no            |
61. |58    |no   |no      |no      |no            |
62. |59    |yes  |no      |no      |no            |
63. |60    |no   |yes     |no      |no            |
64. |61    |yes  |no      |no      |no            |
65. |62    |no   |no      |no      |no            |
66. |63    |no   |no      |yes     |no            |
67. |64    |no   |no      |no      |no            |
68. |65    |no   |yes     |no      |no            |
69. |66    |no   |no      |no      |no            |
70. |67    |yes  |no      |no      |no            |
71. |68    |no   |no      |no      |no            |
72. |69    |no   |no      |no      |no            |
73. |70    |no   |yes     |yes     |yes           |
74. |71    |yes  |no      |no      |no            |
75. |72    |no   |no      |no      |no            |
76. |73    |yes  |no      |no      |no            |
77. |74    |no   |no      |no      |no            |
78. |75    |no   |yes     |no      |no            |
79. |76    |no   |no      |no      |no            |
80. |77    |no   |no      |yes     |no            |
81. |78    |no   |no      |no      |no            |
82. |79    |yes  |no      |no      |no            |
83. |80    |no   |yes     |no      |no            |
84. |81    |no   |no      |no      |no            |
85. |82    |no   |no      |no      |no            |
86. |83    |yes  |no      |no      |no            |
87. |84    |no   |no      |yes     |no            |
88. |85    |no   |yes     |no      |no            |
89. |86    |no   |no      |no      |no            |
90. |87    |no   |no      |no      |no            |
91. |88    |no   |no      |no      |no            |
92. |89    |yes  |no      |no      |no            |
93. |90    |no   |yes     |no      |no            |
94. |91    |no   |no      |yes     |no            |
95. |92    |no   |no      |no      |no            |
96. |93    |no   |no      |no      |no            |
97. |94    |no   |no      |no      |no            |
98. |95    |no   |yes     |no      |no            |
99. |96    |no   |no      |no      |no            |
100. |97    |yes  |no      |no      |no            |
101. |98    |no   |no      |yes     |no            |
102. |99    |no   |no      |no      |no            |
103. |100   |no   |yes     |no      |no            |
104. +------+-----+--------+--------+--------------+
105. Calculated in 0 milliseconds
106.  

Code is hidden, SHOW

Thanks for the advice gmmastros, you're a legend.

[gmmastros]

Well done.

[chrissie1]

My first try in C#

csharpLine number Off | Show | Select all

1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Text;
5. using System.Diagnostics;
6.  
7. namespace ConsoleApplication1
8. {
9.     class Program
10.     {
11.         static void Main(string[] args)
12.         {
13.             Stopwatch stopwatch = new Stopwatch();
14.             stopwatch.Start();
15.             for (int x=1; x < 100; x++)
16.             {
17.                 StringBuilder result = new StringBuilder(100);
18.                 result.Append(x);
19.                 result.Append(" ");
20.                 if (x % 5 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
21.                 if (x % 7 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
22.                 if (x % 35 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
23.                 if (IsPrime(x)) { result.Append("yes  "); } else { result.Append("no   "); }
24.                 Console.WriteLine(result.ToString());
25.             }
26.             Console.WriteLine(stopwatch.ElapsedMilliseconds);
27.             Console.ReadLine();
28.         }
29.  
30.         public static Boolean IsPrime(int x)
31.         {
32.             bool isPrimeNumberFound = true;
33.            
34.             //Get Square root of number and iterate, start from 2
35.             int check = (int)Math.Sqrt((double)(x));
36.             for (int j = 2; j <= check; j++)
37.             {
38.                 if (x % j == 0)
39.                 {
40.                     isPrimeNumberFound = false;
41.                     break;
42.                 }
43.             }
44.             return isPrimeNumberFound;
45.         }
46.     }
47. }
48.  

Code is hidden, SHOW

45 ms on my system.

[chrissie1]

uhm this is weird. I couldn't get it any faster in a console app. So George tried as a windows app and there nearly the same code runs in 0 ms.

[SQLDenis]

Chrissie,

In that case a WPF app should be the fastest

[chrissie1]

Well the solution was simple as dirt.

csharpLine number Off | Show | Select all

1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Text;
5. using System.Diagnostics;
6.  
7. namespace ConsoleApplication1
8. {
9.     class Program
10.     {
11.         static void Main(string[] args)
12.         {
13.             Stopwatch stopwatch = new Stopwatch();
14.             StringBuilder result = new StringBuilder(10000);
15.             stopwatch.Start();
16.             for (int x=1; x < 10000; x++)
17.             {
18.                 result.Append(x);
19.                 result.Append(" ");
20.                 if (x % 5 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
21.                 if (x % 7 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
22.                 if (x % 35 == 0) { result.Append("yes  "); } else { result.Append("no   "); }
23.                 if (IsPrime(x)) { result.Append("yes  "); } else { result.Append("no   "); }
24.                 result.Append(Environment.NewLine);
25.             }
26.             var time = stopwatch.ElapsedMilliseconds;
27.             Console.WriteLine(result.ToString());
28.             Console.WriteLine(time);
29.             Console.ReadLine();
30.         }
31.  
32.         public static Boolean IsPrime(int x)
33.         {
34.             bool isPrimeNumberFound = true;
35.            
36.             //Get Square root of number and iterate, start from 2
37.             int check = (int)Math.Sqrt((double)(x));
38.             for (int j = 2; j <= check; j++)
39.             {
40.                 if (x % j == 0)
41.                 {
42.                     isPrimeNumberFound = false;
43.                     break;
44.                 }
45.             }
46.             return isPrimeNumberFound;
47.         }
48.     }
49. }
50.  
51.  

Code is hidden, SHOW

8 ms for 10000 elements on my machine.

[HarleyQuinn]

VB6 version I wrote when Denis first suggested this puzzle (I've modifed the timing to be consistent with George's version). Runs at almost exactly same speeds as George's as well.

vbLine number Off | Show | Select all

1. Private Sub cmdPrimeTest_Click()
2.     Dim NotPrime(10000) As Boolean
3.     Dim prime As Long
4.     Dim i As Long
5.     Dim blnPrime As Boolean
6.     Dim blnFive As Boolean
7.     Dim blnSeven As Boolean
8.     Dim arrOutPut(1 To 10000) As String
9.    
10.     Dim Start As Single
11.    
12.     Start = Timer
13.    
14.     arrOutPut(1) = 1 & vbTab & False & vbTab & False & vbTab & False & vbTab & False
15.    
16.     For prime = 2 To 10000
17.    
18.         blnPrime = False
19.         blnFive = Not CBool(prime Mod 5)
20.         blnSeven = Not CBool(prime Mod 7)
21.        
22.         If Not NotPrime(prime) Then
23.             blnPrime = True
24.             For i = prime * 2 To 10000 Step prime
25.                 NotPrime(i) = True
26.             Next
27.         End If
28.        
29.         arrOutPut(prime) = prime & vbTab & blnPrime & vbTab & blnFive & vbTab & blnSeven & vbTab & (blnFive And blnSeven)
30.        
31.     Next
32.    
33.     Text3.Text = Join(arrOutPut, vbCrLf)
34.    
35.     MsgBox Format((Timer - Start) * 1000, "0.000") & " milliseconds"
36. End Sub

Code is hidden, SHOW

edited by chrissie1: used hidecode tags

Cheers for the edit Chrissie

[HarleyQuinn]

Grr, and my C# implementation of it was 3ms slower than Chrissie's

[chrissie1]

That's why I wrote that song for Tina Turner.

[HarleyQuinn]

I was going for it being because I've only been writing C# for a week and a half

[AlexCuse]

quick and dirty F#, painfully slow

ocamlLine number Off | Show | Select all

1. #light
2. open System
3.  
4. let rec isPrime (n:int) (i:int)=
5.     if n = 1 then
6.         false
7.     elif i >= (int)(Math.Sqrt((double)n)) then
8.         true
9.     elif n % i = 0 then
10.         false
11.     else
12.         isPrime n (i + 1 + (i % 2))
13.  
14. let start = DateTime.Now  
15. printfn "n, div5, div7, div35, prime"
16. [1..100]|>Seq.iter(fun x-> printfn "%d, %b, %b, %b, %b" x (x % 5 = 0) (x % 7 = 0) (x % 35 = 0) (isPrime x 2))
17. printfn "finished in %d" (((DateTime.Now - start).Seconds * 1000) + (DateTime.Now - start).Milliseconds)

Code is hidden, SHOW

[shamsm]

Here is my solution in Java

javaLine number Off | Show | Select all

1.  
2. public class Puzzle19 {
3.  
4.     public static void main(String[] args) {
5.  
6.         final long startTime = System.nanoTime();
7.  
8.         // records[i][0] = true if not prime
9.         // records[i][1] = true if divisible by 5
10.         // records[i][2] = true if divisible by 7
11.         boolean[][] records = new boolean[101][3];
12.     records[1][0] = true;
13.     records[5][1] = true;
14.     records[7][2] = true;
15.         StringBuilder result = new StringBuilder(5000);
16.  
17.         int[] primesLessThan50 = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41,
18.                 43, 47 };
19.  
20.         // Compute the non-primes
21.         for (int j : primesLessThan50) {
22.             int start = j * 2;
23.             boolean isFive = (j == 5);
24.             boolean isSeven = (j == 7);
25.             while (start <= 100) {
26.                 records[start][0] = true;
27.                 if (isFive) {
28.                     records[start][1] = true;
29.                 }
30.                 if (isSeven) {
31.                     records[start][2] = true;
32.                 }
33.                 start += j;
34.             }
35.         }
36.  
37.         result.append("number   prime   div by 5   div by 7   div by 5 and 7\n");
38.         for (int i = 1; i < 101; i++) {
39.             final String isPrime = !records[i][0] ? "yes" : "no";
40.             final String isDivisbleBy5 = records[i][1] ? "yes" : "no";
41.             final String isDivisbleBy7 = records[i][2] ? "yes" : "no";
42.             final String isDivisbleBy35 = (records[i][1] && records[i][2]) ? "yes"
43.                     : "no";
44.             result.append(String.format("%5d%9s%10s%10s%12s\n", i, isPrime,
45.                     isDivisbleBy5, isDivisbleBy7, isDivisbleBy35));
46.         }
47.         System.out.println(result);
48.         final long endTime = System.nanoTime();
49.         System.out.println(String.format("Total Time %10.4f ms",
50.                 (endTime - startTime) / 1000000.0));
51.     }
52.  
53. }

Code is hidden, SHOW

textLine number Off | Show | Select all

1. number   prime   div by 5   div by 7   div by 5 and 7
2.     1      yes        no        no          no
3.     2      yes        no        no          no
4.     3      yes        no        no          no
5.     4       no        no        no          no
6.     5      yes        no        no          no
7.     6       no        no        no          no
8.     7      yes        no        no          no
9.     8       no        no        no          no
10.     9       no        no        no          no
11.    10       no       yes        no          no
12.    11      yes        no        no          no
13.    12       no        no        no          no
14.    13      yes        no        no          no
15.    14       no        no       yes          no
16.    15       no       yes        no          no
17.    16       no        no        no          no
18.    17      yes        no        no          no
19.    18       no        no        no          no
20.    19      yes        no        no          no
21.    20       no       yes        no          no
22.    21       no        no       yes          no
23.    22       no        no        no          no
24.    23      yes        no        no          no
25.    24       no        no        no          no
26.    25       no       yes        no          no
27.    26       no        no        no          no
28.    27       no        no        no          no
29.    28       no        no       yes          no
30.    29      yes        no        no          no
31.    30       no       yes        no          no
32.    31      yes        no        no          no
33.    32       no        no        no          no
34.    33       no        no        no          no
35.    34       no        no        no          no
36.    35       no       yes       yes         yes
37.    36       no        no        no          no
38.    37      yes        no        no          no
39.    38       no        no        no          no
40.    39       no        no        no          no
41.    40       no       yes        no          no
42.    41      yes        no        no          no
43.    42       no        no       yes          no
44.    43      yes        no        no          no
45.    44       no        no        no          no
46.    45       no       yes        no          no
47.    46       no        no        no          no
48.    47      yes        no        no          no
49.    48       no        no        no          no
50.    49       no        no       yes          no
51.    50       no       yes        no          no
52.    51       no        no        no          no
53.    52       no        no        no          no
54.    53      yes        no        no          no
55.    54       no        no        no          no
56.    55       no       yes        no          no
57.    56       no        no       yes          no
58.    57       no        no        no          no
59.    58       no        no        no          no
60.    59      yes        no        no          no
61.    60       no       yes        no          no
62.    61      yes        no        no          no
63.    62       no        no        no          no
64.    63       no        no       yes          no
65.    64       no        no        no          no
66.    65       no       yes        no          no
67.    66       no        no        no          no
68.    67      yes        no        no          no
69.    68       no        no        no          no
70.    69       no        no        no          no
71.    70       no       yes       yes         yes
72.    71      yes        no        no          no
73.    72       no        no        no          no
74.    73      yes        no        no          no
75.    74       no        no        no          no
76.    75       no       yes        no          no
77.    76       no        no        no          no
78.    77       no        no       yes          no
79.    78       no        no        no          no
80.    79      yes        no        no          no
81.    80       no       yes        no          no
82.    81       no        no        no          no
83.    82       no        no        no          no
84.    83      yes        no        no          no
85.    84       no        no       yes          no
86.    85       no       yes        no          no
87.    86       no        no        no          no
88.    87       no        no        no          no
89.    88       no        no        no          no
90.    89      yes        no        no          no
91.    90       no       yes        no          no
92.    91       no        no       yes          no
93.    92       no        no        no          no
94.    93       no        no        no          no
95.    94       no        no        no          no
96.    95       no       yes        no          no
97.    96       no        no        no          no
98.    97      yes        no        no          no
99.    98       no        no       yes          no
100.    99       no        no        no          no
101.   100       no       yes        no          no
102.  

Code is hidden, SHOW

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1. Total Time    50.9375 ms
2.  

Edited:
Added initialization code for setting 1 as not prime and 5 and 7 to be divisble by themselves
Time is being printed after sysout of the result string

[gmmastros]

There are a couple of minor problems.

1 is not a prime number.
5 is divisible by 5
7 is divisible by 7