alienabc.cpp

// NOTE: it is recommended to use this even if you don't understand the following code.

#include <fstream>
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
  // uncomment the following lines if you want to read/write from files
  // ifstream cin("input.txt");
  // ofstream cout("output.txt");
  
  int T;
  cin >> T;
  
  for (int test = 0; test < T; test++) {
    string S, temp;
    cin >> S;
    
    // insert your code here
    vector<string> letter;
    letter.clear();
    
    for (int i=0; i< S.size(); i++) {
    	temp = "";
    	if (i != S.size()-1) {
    		if (S[i] == S[i+1]) {
	    		temp += S[i];
	    		temp += S[i+1];
	    		i++;
			} else {
				temp = S[i];
			}
		} else {
			temp = S[i];
		}
		
		if (count(letter.begin(), letter.end(), temp) == 0) {
			letter.push_back(temp);
		} else {
			letter.push_back("-1");
		}
	}
	
	if (count(letter.begin(), letter.end(), "-1") == 0) {
		for (int i=0; i<letter.size(); i++) {
			cout << letter[i] << " ";
		}
		cout << endl;
	} else {
		cout << -1 << endl;
	}
    
  }
  return 0;
}