P1577二分答案70求助

#include<bits/stdc++.h>
#define LL long long
using namespace std;
double a[100000];
LL n,m;
int coke(int x)
{
	int sum=0;
	for(int i=1;i<=n;i++)
	{
		sum+=a[i]/x;
	}
	return sum>=m;
}
int xiaomao()
{
	int l=100,r=10000000;
	while(l<=r)
	{
		int mid=(l+r)/2;
		if(mid==0)
		{
			break;
		}
		if(coke(mid))
		{
			l=mid+1;
		}
		else
		{
			r=mid-1;
		}
	}
	return r;
}
int main()
{
	cin>>n>>m;
	for(LL i=1;i<=n;i++)
	{
		cin>>a[i];
		a[i]=a[i]*100;
	}
	sort(a+1,a+1+n);
	cout<<fixed<<setprecision(2)<<xiaomao()/100.0;
	return 0;
}