全部RE

#include<bits/stdc++.h>
using namespace std;
string decode(){
	int num;
	string a="",a2;
	char zi;
	while (cin>>zi){
		if(zi=='['){
			cin>>num;
			a2=decode();
			while (num--) a+=a2;
		}
		else {
			if (zi==']') return a;
		    else a+=zi;
		}
	}
}
int main(){
	cout<<decode();
	return 0;
}

求助大佬！！！

Q_Q