題解：

woc竟然有個小地方沒看出錯來，WA了半天

DP一下

註意爆long long

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
typedef long long Lint;
 
int n;
Lint m;
 
int ans=0x7fffffff;
Lint f[130][300000]={0};
int k[130],c[130],sumcost=0;
 
int main(){
    scanf("%d%lld",&n,&m);
    for(int i=1;i<=n;++i)scanf("%d",&k[i]);
    for(int i=1;i<=n;++i)scanf("%d",&c[i]);
    for(int i=1;i<=n;++i)sumcost=sumcost+k[i]*c[i];
     
    f[1][0]=1;
    for(int i=2;i<=k[1];++i)f[1][i*c[1]]=i;
    for(int i=1;i<n;++i){
    	for(int j=0;j<=sumcost;++j)f[i+1][j]=max(f[i+1][j],f[i][j]);
        for(int a=2;a<=k[i+1];++a){
            for(int j=0;j<=sumcost;++j){
                f[i+1][j+a*c[i+1]]=min(m,max(f[i+1][j+a*c[i+1]],f[i][j]*a));
            }
        }
    }
    
//    for(int i=0;i<=sumcost;++i)cout<<f[1][i]<<‘ ‘;
//    cout<<endl;
    for(int j=0;j<=sumcost;++j){
        if(f[n][j]>=m)ans=min(ans,j);
    }
     
    cout<<ans<<endl;
    return 0;
}

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