poj 1552 Doubles

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 int nums[16];
 4 
 5 int cmp(const void *a, const void *b)
 6 {
 7     return *(int*)a - *(int*)b;
 8 }
 9 
10 int main()
11 {
12     int n,i,j,result;
13     while(scanf("%d",&n) && n != -1)
14     {
15         i = result = 0;
16         nums[i] = n;
17         ++i;
18         while(scanf("%d",&n) && n)
19         {
20             nums[i] = n;
21             ++i;
22         }
23 
24         n = i;
25         qsort(nums,i,sizeof(nums[0]),cmp);
26         for(i = 0; i < n; ++i)
27         {
28             for(j = i+1; j < n; ++j)
29             {
30                 if(nums[j]/nums[i] == 2 && nums[j]%nums[i] == 0)
31                 {
32                     ++result;
33                     break;
34                 }
35             }
36         }
37         printf("%d\n",result);
38     }
39 }