POJ 2976 0-1分数规划入门

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
#define ll long long

double a[1005],b[1005];
double d[1005];
int main ()
{
ll n,k;
while(scanf("%lld%lld",&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 left=0.0,right=1.0,mid;
while(right-left>0.000001)
{
mid=(left+right)/2;
for(int i=1;i<=n;++i)
d[i]=a[i]-mid*b[i];
sort(d+1,d+1+n);
double res=0.0;
for(int i=k+1;i<=n;++i)
res+=d[i];
if(res>0.0)
left=mid;
else right=mid;
}
// round
int ans=left*100+0.5000001;
cout<<ans<<endl;
}
return 0;
}