蒟蒻求助

#include<bits/stdc++.h>
using namespace std;
vector<string>a,b;
string t;
int n,m;
string f(string x){
	int t[50] = {0};
	string ret="";
	for(int i = 0;i<x.size();i++)t[x[i]-'a']++;
	for(int i = 'z';i>='a';i--)
		for(int j = 0;j<t[i-'a'];j++)ret = (char)i+ret;
	return ret;
}
int main(){
	cin>>n>>m;
	for(int i = 0;i<n;i++){
		cin>>t;
		a.push_back(t);
	}
	for(int i =0 ;i<n;i++){
		b = a;
		t = f(a[i]);
		b[i] = t;
		sort(b.begin(),b.end());
		if(b[0]==t)cout<<1;
		else cout<<0;
	}
} 

望各位大佬指点