标签:hdu2098
30 26 0
3 2
#include <stdio.h> #include <math.h> #define maxn 10002 int prime[maxn] = {1, 1}; int main() { int i, n, j, ans; n = sqrt(maxn); for(i = 2; i <= n; ++i){ if(prime[i]) continue; for(j = i * i; j <= maxn; j += i) prime[j] = 1; } while(scanf("%d", &n), n){ j = n >> 1; ans = 0; for(i = 2; i < j; ++i) if(!prime[i] && !prime[n - i]) ++ans; printf("%d\n", ans); } return 0; }
标签:hdu2098
原文地址:http://blog.csdn.net/chang_mu/article/details/38085103