[poj 2976] Dropping tests （分数规划 二分）

//By Menteur_Hxy
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <map>
#include <vector>
#define M(a,b) memset(a,(b),sizeof(a))
#define F(i,a,b) for(register int i=(a);i<=(b);i++)
#define LL long long
using namespace std;

inline LL rd() {
    LL x=0,fla=1; char c=‘ ‘;
    while(c>‘9‘|| c<‘0‘) {if(c==‘-‘) fla=-fla; c=getchar();}
    while(c<=‘9‘ && c>=‘0‘) x=x*10+c-‘0‘,c=getchar();
    return x*fla;
}

const int N=1010;
const int INF=0x3f3f3f3f;
int n,k;
int a[N],b[N];
double t[N];

double jud(double L) { double sum=0.0;
    F(i,1,n) t[i]=a[i]-L*b[i];
    sort(t+1,t+1+n);
    F(i,k+1,n) sum+=t[i];
    return sum;
}

int main() {
    while(scanf("%d %d",&n,&k),n||k) {
        F(i,1,n) a[i]=rd(); 
        F(i,1,n) b[i]=rd();
        double l=0.0,r=1.0;
        while(r-l>1e-7) {
            double mid=(l+r)/2;
            if(jud(mid)>0) l=mid;
            else r=mid;
        }
        printf("%.0f\n",l*100);
    }
    return 0;
}