Java Hashset

• 문제
  
• 정답

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

 public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int t = s.nextInt();
        String [] pair_left = new String[t];
        String [] pair_right = new String[t];
        
        for (int i = 0; i < t; i++) {
            pair_left[i] = s.next();
            pair_right[i] = s.next();
        }

        Set<String> uniquePairs = new HashSet<>();
        
        for (int i = 0; i < t; i++) {
            String a = pair_left[i];
            String b = pair_right[i];
            
            String sortedPair = (a.compareTo(b) < 0) ? a + " " + b : b + " " + a;
            
            uniquePairs.add(sortedPair);
            
            System.out.println(uniquePairs.size());
        }
        
        s.close();

   }
}

• 결과