(DS1.4.)poj 1552 Doubles(测试组数和每组测试用例的个数不定)

#include <iostream>#include <cstdio>using namespace std;const int maxn  = 20;int main(){int a[maxn];cin >> a[0];while(a[0] != - 1){int i = 1,j,count = 0;for(; ; i++){scanf("%d",&a[i]);if(a[i] == 0){break;}}int n = i;for(i = 0 ; i < n - 1 ; ++i){for(j = i + 1 ; j < n ;++j ){if(a[i]*2 == a[j] || a[j]*2 == a[i]){count++;}}}printf("%d\n",count);cin >> a[0];}return 0;}