[SW Expert Academy] 민정이와 광직이의 알파벳 공부 (D3)

https://swexpertacademy.com/main/code/problem/problemDetail.do?problemLevel=3&contestProbId=AXAdrmW61ssDFAXq&categoryId=AXAdrmW61ssDFAXq&categoryType=CODE&problemTitle=%EB%AF%BC%EC%A0%95%EC%9D%B4%EC%99%80&orderBy=INQUERY_COUNT&selectCodeLang=ALL&select-1=3&pageSize=10&pageIndex=1

SW Expert Academy

 

import java.util.HashSet;
import java.util.Scanner;

class Solution {
	
	public static int result,n;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		int t = sc.nextInt();
		
		for(int tc=1;tc<=t;tc++) {
			result=0;
			n = sc.nextInt();
			String word[] = new String[n];
			
			for(int i=0;i<n;i++) {
				word[i] = sc.next();
			}
			
			combination(0,word,new HashSet<>());
			
			System.out.println("#"+tc+" "+result);
		}
	}
	
	static void combination(int depth,String[] word,HashSet<Character> s) {
		
		HashSet<Character> hs = new HashSet<>(s);
		
		if(depth==n) { //선택 n개 만큼 하면 종료
			if(hs.size()==26) {
				result++;
			}
			return;
		}
		
		combination(depth+1,word,hs); //선택 안 함
		for(char ch: word[depth].toCharArray()) {
			hs.add(ch);
		}
		combination(depth+1,word,hs); //선택함
		
	}
	
	
	
}