[SWEA] 11856. 반반_JAVA

https://swexpertacademy.com/main/code/problem/problemDetail.do?contestProbId=AXjS1GXqZ8gDFATi 

SW Expert Academy

 

자료구조 set을 이용하면 간단히 클리어 

import java.util.Scanner;
import java.util.HashSet;
class Solution{
	public static void main(String args[]) throws Exception{
		Scanner sc = new Scanner(System.in);
		int T;
		T=sc.nextInt();
		for(int test_case = 1; test_case <= T; test_case++) {
                char[] text = sc.next().toCharArray();
            	HashSet<Character> s = new HashSet<>();
                 for(int i=0;i<4;i++)
                   	  s.add(text[i]);
            System.out.println("#"+test_case+" "+(s.size()==2 ? "Yes":"No"));
		}
	}
}