【题解】Luogu P4377 Talent Show

//
//  main.cpp
//  Luogu
//
//  Created by gengyf on 2019/7/7.
//  Copyright © 2019 yifan Geng. All rights reserved.
//

#include <bits/stdc++.h>
using namespace std;
int n,W;
int w[300],t[300];
long long f[10005];
bool check(int x){
    memset(f,128,sizeof(f));
    f[0]=0;
    long long tmp=f[W];
    for(int i=1;i<=n;i++)
        for(int j=W;j>=0;j--){
            if(f[j]!=tmp){
                int y=j+w[i];
                y=min(y,W);
                f[y]=max(f[y],f[j]+t[i]-(long long)w[i]*x);
            }
        }
    return f[W]>=0;
}
int main(){
    scanf("%d%d",&n,&W);
    for(int i=1;i<=n;i++){
        scanf("%d%d",&w[i],&t[i]);
        t[i]*=1000;
    }
    int l=0,r=1000000;
    while(l<=r){
        int mid=(l+r)>>1;
        if(check(mid))l=mid+1;
        else r=mid-1;
    }
    printf("%d",l-1);
    return 0;
}