pku acm 1064

#include <iostream>
#include <cstdio>
#include <iomanip>
using namespace std;

int intCables[10002];//单位cm

bool numberCuts(int index,int k,int length)//cm单位
{
long long lnums = 0;
for (int i = 0; i < index; ++i)
{
lnums += intCables[i]/length;
if (lnums >= k)return true;
}

return false;
}

int main()
{
freopen("in.txt","r",stdin);

int N,K;// 1 <= N, K <= 10000
int index = 0;
float fCable;
cin>>N>>K;
while (N--)
{
cin>>fCable;//单位是m
intCables[index++] = (int)(1000*fCable+5)/10;//转换成cm存储
}

int left = 1,right = 10000000;
int mid, ans = 0;
while (left <= right)
{
mid = (left + right)/2;
if (numberCuts(index,K,mid))
{
ans = mid; //这里很关键
left = mid + 1;
}
else
right = mid - 1;
}

if (ans < 1)
cout<<"0.00"<<endl;
else
cout<<fixed<<setprecision(2)<<(ans*1.0/100)<<endl;
}