题目网址:https://517coding.com/p/4090
Wrong Answer 4个点
代码如下:
#include<bits/stdc++.h>
using namespace std;
int v[100005],w[100005];
double a[100005];
int n,k;
int comp(int x,int y){
return x>y;
}
bool check(double ans){
for(int i=0;i<n;i++){
a[i]=v[i]-w[i]*ans;
}
sort(a,a+n,comp);
double sum=0;
for(int i=0;i<k;i++)sum+=a[i];
if(sum>=0)return true;
return false;
}
int main(){
scanf("%d%d",&n,&k);
for(int i=0;i<n;i++){
scanf("%d%d",&v[i],&w[i]);
}
double l=0,r=1e7,cnt=100,best=0;
while(cnt--){
double mid=(l+r)/2;
if(check(mid))l=mid,best=mid;
else r=mid;
}
printf("%.2lf",best);
return 0;
}