// [문제 링크]: https://school.programmers.co.kr/learn/courses/30/lessons/120875 import java.util.HashMap; class Solution { public int solution(int[][] dots) { int answer = 0; HashMap hash = new HashMap<>(); for(int a = 0; a < dots.length-1; a++){ for(int b = a+1; b < dots.length; b++){ hash.put((double) (dots[a][1]-dots[b][1])/(dots[a][0]-dots[b][0]),hash.getOrDefault((double) (dots[a][1]-dots[b][1])/(dots[a][0]-dots[b][0]),0)+1); } } for(double key : hash.keySet()){ if(hash.get(key)>1) { answer = 1; break; } } return answer; } }