hdoj 1203 I NEED A OFFER! 【另类01背包】【概率背包】

#include<string.h>
#include<stdio.h>
double dp[10010];
struct node{
    int a;
    double b;
}s[10010];
int main()
{
    int n, m, i, j;
    while(scanf("%d%d", &n, &m), n||m){
        for(i = 0; i <= n; i ++) dp[i] = 1;//因为是求概率所以要初始化为1
        for(i = 0; i < m; i ++){
            scanf("%d%lf", &s[i].a, &s[i].b);
        }
        for(i = 0; i < m; i ++){
            for(j = n; j >= s[i].a; j --){
                if(dp[j] > dp[j-s[i].a]*(1-s[i].b)) dp[j] = dp[j-s[i].a]*(1-s[i].b);
            }
        }
        printf("%.1f%%\n", (1-dp
)*100);
    }
}