2115.cpp

这是哈尔滨工业大学acmOJ的源代码

/*  This Code is Submitted by wywcgs for Problem 2115 on 2005-10-07 at 22:13:39 */ 
#include <cstdio>
#include <cstdlib>
#include <cmath>
#define  MAX  32

int cmp(const void*, const void*);

int main()
{
	double r[MAX], sum;
	int K, i, j, k, p;
	bool comp;
	
	while(scanf("%d", &K) == 1) {
		if(K == 0) {
			return 0;
		} else {
			for(i = 0; i < K; i++) {
				scanf("%lf", &r[i]);
			}
			qsort(r, K, sizeof(double), cmp);
			comp = false;
			for(i = 1; i < K; i++) {
				p = K - i;
				for(j = 1; j <= p; j++) {
					sum = 0;
					for(k = j; k < j + i; k++) {
						sum += r[k];
					}
					if(sum - r[j-1] > 1e-4 || fabs(sum - r[j-1]) < 1e-4) {
						comp = true;
						break;
					}
				}
				if(comp) {
					break;
				}
			}
			if(comp) {
				printf("YES\n");
			} else {
				printf("NO\n");
			}
		}
	}
	
	return 0;
}

int cmp(const void *a, const void *b)
{
	if(*(double*)a - *(double*)b < 1e-4) {
		return 1;
	} else {
		return -1;
	}
}