p1577 14分求助

#include<bits/stdc++.h>
using namespace std;
double n,k,a[2115114],l=0,r=114514000,mid;
double cd(double b){
	double changdu=0;
	for(int i=0;i<n;i++)changdu+=a[i]/b;
	if(changdu>=k)return 114514;
	else return 0;
}
int main(){
	cin>>n>>k;
	for(int i=0;i<n;i++)cin>>a[i];
	while(l+1<r){
		mid=(l+r)/2;
		if(mid==0){
			cout<<"0.00";
			return 0;
		}
		if(cd(mid))l=mid;
		else r=mid;
	}
	printf("%.2lf",l);
	return 0;
}