[programmers][X] 시소 짝꿍

04 Jul 2023 in Algorithm on Algorithm

https://school.programmers.co.kr/learn/courses/30/lessons/152996

import java.util.*;

class Solution {
    public long solution(int[] weights) {
        long answer = 0;

        Arrays.sort(weights);

        Map<Double,Integer> m = new HashMap<>();

        for(int w : weights){
            Double d = w*1.0;

            answer += m.getOrDefault(d,0);
            answer += m.getOrDefault(d/2,0);
            answer += m.getOrDefault(d*2/3,0);
            answer += m.getOrDefault(d*3/4,0);

            m.put(d,m.getOrDefault(d,0)+1);
        }

        return answer;
    }
}