hdu 1009 肥胖鼠 貪心（一） sort 排序函數

#include<iostream>
#include<iomanip>
#include<algorithm>
using namespace std;
struct Trade
{
    int j,f;
    double percent;
}mouse[3001];
bool cmp(Trade a,Trade b)
{
    return a.percent>b.percent;
}
int main()
{
    int n,m;
    while(cin>>m>>n&&(n!=-1||m!=-1))  // 括號不能玩丟了
    {
        int i;
       
        for(i=0;i<n;i++)
        {
            cin>>mouse[i].j>>mouse[i].f;
            mouse[i].percent=(double)mouse[i].j/mouse[i].f;
        }
        sort(mouse,mouse+n,cmp);
        double sum=0;
        for(i=0;i<n;i++)
        {
            if(m>mouse[i].f)
                 {
                     sum+=mouse[i].j;
                     m-=mouse[i].f;
                 }
            else
                //break;
            {
                sum+=mouse[i].percent*m; // m即所剩coffeeBean
                m=0;
                break;
            }
                    
                       
        }
       
       cout<<fixed<<setprecision(3)<<sum<<endl;  //保留三位小數
       
    }
    return 0;
}