[P1208]混合牛奶

原题链接

一遍过
贪心

#include<iostream>#include<cstdio>#include<cstring>#include<string>#include<cmath>#include<algorithm>#include<queue>#include<vector>using namespace std;struct nico{    int a,p;}f[5000+5];int comp(nico a,nico b){    return a.p<b.p;}int m,n,i,p;int main(){    scanf("%d%d",&n,&m);    for(i=1;i<=m;i++)        scanf("%d%d",&f[i].p,&f[i].a);    sort(f+1,f+m+1,comp);    i=1;    while(n)    {        if(n>f[i].a)        {            n-=f[i].a;            p+=f[i].p*f[i].a;            i++;        }        else        {            p+=f[i].p*n;                        n=0;        }    }    printf("%d",p);    return 0;}