最后两个点WA,求帮助qwq
#include<bits/stdc++.h>
using namespace std;
int n,m;
struct cow{
int price,num;
}c[5005];
bool cmpc(cow x,cow y)
{
return x.price<y.price;
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=m;i++)
scanf("%d%d",&c[i].price,&c[i].num);
sort(c+1,c+m+1,cmpc);
long long money=0;
for(int i=1;i<=n;i++)
{
if(n<c[i].num)
{
money+=c[i].price*(c[i].num-n);
break;
}
money+=c[i].price*c[i].num;
n-=c[i].num;
}
printf("%lld",money);
return 0;
}