P1987 摇钱树

题面

https://www.luogu.org/problem/P1987

题解

// luogu-judger-enable-o2
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
struct tree {
  long long m,b;
  bool operator < (const tree rhs) const {
    return b<rhs.b;
  }
} a[1050];
long long n,yourk,f[1050];
using namespace std;
const long long INF=1e8;
int main(){
  long long i,j,v;
  while (true) {
    scanf("%lld %lld",&n,&yourk);
    if (n==0 && yourk==0) return 0;
    for (i=1;i<=n;i++) scanf("%lld",&a[i].m);
    for (i=1;i<=n;i++) scanf("%lld",&a[i].b);
    sort(a+1,a+n+1);
    memset(f,0,sizeof(f));
    f[0]=0;
    for (i=n;i>=1;i--) 
      for (j=yourk;j;j--) {
        v=a[i].m-(j-1)*a[i].b;
        if (v<0) v=0;
        if (f[j-1]+v>f[j]) f[j]=f[j-1]+v;
      }
    long long ans=0;
    for (i=1;i<=yourk;i++) if (f[i]>ans) ans=f[i];
    cout<<ans<<endl;
  }
}