/上天啊 难道你看不出我很爱她/ #include<bits/stdc++.h> using namespace std; struct Node{ double m,v; double avg; }a[110]; bool cmp(Node x,Node y) { return x.avg>y.avg; } int main() { int n,t;cin>>n>>t; for(int i = 1;i<=n;i++) { cin>>a[i].m>>a[i].v; a[i].avg = a[i].v/a[i].m; } sort(a+1,a+1+n,cmp); double sum = 0; for(int i = 1;i<=n;i++) { if(t>=a[i].m) { sum = sum+a[i].v; t = t-a[i].m; } else { sum = sum+t1.0a[i].avg; break; } } cout<<fixed<<setprecision(2)<<sum; }