백준 https://www.acmicpc.net/workbook/view/6152 프로그래머스 https://school.programmers.co.kr/ 깃허브 https://github.com/tony9402/baekjoon 코드업 https://www.codeup.kr/ GeeksforGeeks https://practice.geeksforgeeks.org/home SW Expert Academy (삼성) https://swexpertacademy.com/main/main.do Codility https://app.codility.com/programmers/ Coding Game https://www.codingame.com/start Codewars https://www.codewars.com/