密码

搞得我都快强迫症了，用string数组写，可是一个CLEAR卡了我一天，难受

#include<iostream>
#include<cstring>
#include<string>
using namespace std;
string a[100005];
int main()
{

	int T, n;
	int s, z;
	bool flag;
	string x;
	cin >> T;
	while(T--)
	{
		cin >> n;
		cin >> x;
		if(n == 1)
		{
			cout << x << endl;
			continue;
		}
		int len = x.size();
		for(int i = 0; i < n; i++)
			a[i].clear();
		s = 0;
		z = 0;
		flag = false;
		while(z < len)
		{
			a[s] += x[z];
			if(flag == false)
				s++;
			else if(flag == true)
				s--;
			if(s == 0)
				flag = false;
			else if(s == (n - 1))
				flag = true;
			z++;
		}
		for(int i = 0;  i < n; i++)
			cout << a[i];
		cout << endl;
	}
	return 0;
}