POJ 2356 Find a multiple

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 using namespace std;
 5 const int maxn = 10010;
 6 int a[maxn],pos[maxn],n;
 7 int main() {
 8     while(~scanf("%d",&n)) {
 9         memset(pos,-1,sizeof pos);
10         bool flag = true;
11         int sum = pos[0] = 0;
12         for(int i = 1; i <= n; ++i) {
13             scanf("%d",a + i);
14             sum = (sum + a[i])%n;
15             if(pos[sum] > -1 && flag) {
16                 printf("%d\n", i - pos[sum]);
17                 for(int j = pos[sum] + 1; j <= i; ++j)
18                     printf("%d\n",a[j]);
19                 flag = false;
20             }
21             pos[sum] = i;
22         }
23     }
24     return 0;
25 }