Aimee

显然是可以继承的

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
using namespace std;
const int maxn=1000001; 
char s[maxn];
int l;
int znx,jdn;
int f[maxn];
int main(){
    scanf("%s",s+1);
    int l=strlen(s+1); 
    for(int i=2;i<=l;++i){
        if(s[i]=='('||s[i]=='['){
            continue;
        }else{
            if((s[i-f[i-1]-1]=='('&&s[i]==')')||s[i-f[i-1]-1]=='['&&s[i]==']'){
                f[i]=f[i-1]+2+f[i-2-f[i-1]];
                if(f[i]>znx){
                    znx=f[i];
                    jdn=i;
                }
            }
        }
    }
    for(int i=jdn-znx+1;i<=jdn;++i){
        cout<<s[i];
    }
    return 0;
}