hdu1009FatMouse's Trade

#include <iostream>#include <cstdio>#include <algorithm>using namespace std;struct inp{int x,y;double c;}node[1005];int cmp(inp a,inp b){return a.c>b.c;}int main(){    int m,n,i;    double j;    while(scanf("%d%d",&m,&n)!=EOF){        if(m==-1&&n==-1) break;        for(i=0;i<n;i++){        cin>>node[i].x>>node[i].y;        node[i].c=node[i].x/(double)node[i].y;}        sort(node,node+n,cmp);        j=0;        for(i=0;i<n;i++){            if(m>=node[i].y){            j+=node[i].x;            m-=node[i].y;            }            else{            j+=m*node[i].c;            break;            }        }        printf("%.3lf\n",j);    }    return 0;}