POJ1064 Cable master(二分)

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
using namespace std;

double a[10005];
int n,k;

void solve(double l,double r)
{
double x;
for(int j=0;j<100;j++)
{
x=(l+r)/2;
int ncount=0;
for(int i=0;i<n;i++)
{
ncount+=(int)(a[i]/x);
}
if(ncount>=k) l=x;
else r=x;
}
printf("%.2f\n",floor(r*100)/100);
}

int main()
{
//freopen("d:\\Test.txt","r",stdin);
double Max;
cin>>n>>k;
for(int i=0;i<n;i++)
{
scanf("%lf",&a[i]);
Max=max(Max,a[i]);
}
solve(0,Max+1);
return 0;
}