hdu2955 dp

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <queue>
#include <cmath>
#include <cstring>
#include <stack>
#include <set>
#include <map>
#include <vector>

using namespace std;
#define INF 0x2fffffff
#define LL long long
#define MAX(a,b) ((a)>(b))?(a):(b)
#define MIN(a,b) ((a)<(b))?(a):(b)
int l[1000];
double w[1000];
double dp[10005][105];

int main(){
    int t;
    cin >> t;
    double a;
    int n;
    while(t--){
        scanf("%lf %d",&a,&n);
        int sum  = 0;

        for(int i = 1;i <= n;i++){
            scanf("%d%lf",&l[i],&w[i]);
            w[i] = 1 -w[i];
            sum += l[i];
        }
        for(int i = 0;i <= sum;i++){
            for(int j = 0;j <= n;j++){
                dp[i][j] = 0;
            }
        }
        dp[0][0] = 1;
        for(int i = 0;i <= sum;i++){
            for(int j = 1;j <= n;j++){
                if(l[j] > i){
                    dp[i][j] = dp[i][j-1];
                }
                else{
                    dp[i][j] = max(dp[i][j-1],dp[i-l[j]][j-1]*w[j]);
                }
            }
        }
        int ans = 0;
        a = 1 - a;
        for(int i = 0;i <= sum;i++){
            if(dp[i][n] >= a ){
                ans = i;
            }
        }
        printf("%d\n",ans);

    }
    return 0;
}

同样是01背包问题，但是这道题变换了一个，这里面的价值现在变成了实数，所以这时候要改变dp的策略