PKU 1064 Cable master

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
#define INF 100000000
int l[10009];
int n, k;
bool C(int len)
{
if (len == 0) return false;
int sum = 0;
for (int i=0; i<n; i++)
{
sum += (int)(l[i] / len);
}
if (sum >= k) return true;
return false;
}

int main()
{
cout.precision(2);
while ( cin >> n >> k )
{
double x;
for (int i=0; i<n; i++) { cin >> x; l[i] = x * 100; }
int low = 0, up = INF;
for (int i=0; i<100; i++)
{
int mid = (low + up) / 2;
if (C(mid)) low = mid;
else up = mid;
}
if (low < 1) puts("0.00");
else cout << fixed << low * 1.0 / 100 << endl;
}
return 0;
}