hdu 2955(Robberies)

揹包變種  dp[j]表示不被抓的概率

#include<cstdio>
#include<algorithm>
#define maxn 109
#include<cstring>
using namespace std;
int  money[maxn];
float caught[maxn],dp[maxn*maxn];
int main()
{
    int T,banks;
    float limits;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%f%d",&limits,&banks);
        int sum=0;
        for(int i=1;i<=banks;i++)
        {
            scanf("%d%f",&money[i],&caught[i]);
            sum+=money[i];
        }

        memset(dp,0,sizeof(dp));
        dp[0]=1.0;
        for(int i=1;i<=banks;i++)
             for(int j=sum;j>=0;j--)
             {

                       dp[j]=max(dp[j],dp[j-money[i]]*(1-caught[i]));
             }
        for(int j=sum;j>=0;j--)
         {
             if(dp[j]>=1-limits)
               {
                      printf("%d\n",j);
                      break;
               }
         }

    }
    return 0;
}