HDU 1203 I NEED A OFFER!【01背包】

大意：01背包

分析：01背包

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxn = 10005;
const int INF = 1000000000;

double dp[maxn];
int cost[maxn];
double prob[maxn];
int main() {
    int n, m;
    while(scanf("%d %d",&n, &m)  && ( n + m ) ) {
        for(int i = 1; i <= m; i++) {
            scanf("%d %lf",&cost[i], &prob[i]);
        }
        for(int i = 0; i <= n; i++) dp[i] = 1.0;
        for(int i = 1; i <= m; i++) {
            for(int j = n; j >= cost[i]; j--) {
                dp[j] = min(dp[j], dp[j - cost[i]] * (1.0 - prob[i]));
            }
        }
        double ans = 1.0 -  dp[n];
        ans *= 100;
        printf("%.1lf%%
",ans);
    }
    return 0;
}