POJ

题意：给出n，m，给出n个电缆，求出满足电缆分割后满足m个的电缆的最大长度

思路：二分分割后的电缆长度，二分时 计算出在当前分割电缆长度下可以有多少个电缆

include <iostream>#include <cstdio>#include <algorithm>#include <set>#include <string>#include <cstring>#include <cmath>using namespace std;typedef long long ll;int n,k;double s[10005];bool cal(double x){    int ans=0;    for(int i=1; i<=n; i++)    {        ans+=(int)(s[i]/x);        if(ans>=k)            return true;    }    return false;}int main(){    scanf("%d%d",&n,&k);    double  l=0,r=0,mid;    for(int i=1; i<=n; i++)    {        scanf("%lf",&s[i]);        r=max(r,s[i]);    }    while(r-l>1e-6)    {        mid=(l+r)/2.0;        if(cal(mid))            l=mid;        else            r=mid;    }    printf("%.2lf\n",int(r*100)*0.01);    return 0;}