HDU-2955-Robberies

#include <iostream>
#include <memory.h>
#include <vector>
#include <map>
#include <algorithm>
#include <cstdio>
#include <math.h>

using namespace std;

typedef long long LL;

const int MAXN = 1e4 + 10;

double dp[MAXN];
int a[MAXN];
double b[MAXN];

int main()
{
    int t;
    int n;
    double v;
    scanf("%d", &t);
    while (t--)
    {
        memset(dp, 0, sizeof(dp));
        scanf("%lf%d", &v, &n);
        v = 1 - v;
        int sum = 0;
        for (int i = 1;i <= n;i++)
        {
            scanf("%d%lf", &a[i], &b[i]);
            sum += a[i];
            b[i] = 1 - b[i];//安全概率
        }
        dp[0] = 1.0;
        for (int i = 1;i <= n;i++)
        {
            for (int j = sum;j >= a[i];j--)
                dp[j] = max(dp[j], dp[j - a[i]] * b[i]);
        }

        for (int i = sum;i >= 0;i--)
            if (dp[i] >= v)
            {
                printf("%d\n", i);
                break;
            }

    }

    return 0;
}