[level 2] 의상 - 42578

문제 링크

프로그래머스

import java.util.HashMap;

class Solution {

    public int solution(String[][] clothes) {
       HashMap<String, Integer> clothesInfo = new HashMap<>();
       for (String[] clothe : clothes) {
          clothesInfo.put(clothe[1], 1 + clothesInfo.getOrDefault(clothe[1], 1));
       }

       return clothesInfo.values().stream().reduce((a, b) -> a * b).orElse(1) - 1;
    }
}