poj2976 Dropping tests

01分数规划裸题

为毛二分一定要打成r=mid这么恶心啊

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
using namespace std;
typedef long long LL;int n,k;
double a[1100],b[1100],c[1100];
double check(double mid)
{for(int i=1;i<=n;i++)c[i]=a[i]-mid*b[i];sort(c+1,c+n+1);double ret=0;for(int i=n;i>k;i--)ret+=c[i];return ret;
}
int main()
{while(scanf("%d%d",&n,&k)!=EOF){if(n==0&&k==0)break;for(int i=1;i<=n;i++)scanf("%lf",&a[i]);for(int i=1;i<=n;i++)scanf("%lf",&b[i]);double l=0,r=1,ans;while(r-l>1e-8){double mid=(l+r)/2;if(check(mid)>0){l=mid;}else r=mid;}printf("%.0lf\n",r*100);}return 0;
}