第三章 poj 1064

#include <iostream>
#include <cmath>
#include <cstdio>

using namespace std;

const int maxn=10000;
const double eps=0.00001;


double Len[maxn];
int n,k;
double Max;

bool Right(double len)
{
	int ans(0);
	for (int i=0;i<n;i++)
	{
		ans+=(int)(Len[i]/len);
	}

	if (ans>=k)
		return true;
	else
		return false;
}

bool Bigger(double a,double b)
{
	if (a-b<=eps)
		return true;
	else
		return false;
}

void Init()
{
	cin>>n>>k;
	for (int i=0;i<n;i++){
		scanf("%lf",&Len[i]);
		Max=max(Max,Len[i]);
	}
}


int main()
{
   // freopen("a.txt","r",stdin);
    Init();
    double ln(0),rn(Max);

    for (int i=1;i<=100;i++)
    {
        double mid=(ln+rn)/2;
        if (Right(mid))
        {
            ln=mid;
        }
        else
        {
            rn=mid;
        }
    }

    rn=(rn+ln)/2;

    printf("%.2f\n",floor(rn*100)/100);


}

#include <iostream>
#include <cstdio>
#include <string>
#include <sstream>
#include <cmath>

using namespace std;

const int maxn=10000;
const double eps=0.001;


double Len[maxn];
int n,k;
double Max;

bool Right(double len)
{
	int ans(0);
	for (int i=0;i<n;i++)
	{
		ans+=(int)(Len[i]/len);
	}

	if (ans>=k)
		return true;
	else
		return false;
}

void Init()
{
	cin>>n>>k;
	Max=0;
	for (int i=0;i<n;i++)
    {
        scanf("%lf",&Len[i]);
        Max=max(Max,Len[i]);
    }

}


int main()
{
    //freopen("a.txt","r",stdin);
    Init();
    double ln(0),rn(Max);

    for (int i=1;i<=100;i++)
    {
        double mid=(ln+rn)/2;
        if (Right(mid))
        {
            ln=mid;
        }
        else
        {
            rn=mid;
        }
    }

    rn=(rn+ln)/2;

    printf("%.2f\n",floor(rn*100)/100);


}