https://www.notion.so/Dynamic-Programming-70f5d74d7b574d4a91829e9503b56ee6
https://www.notion.so/e518492f61ff41db8313c3574af6219c
https://www.opentutorials.org/module/2980/17535
https://dailyheumsi.tistory.com/67 https://wayhome25.github.io/python/2017/03/07/key-function/
https://blog.hexabrain.net/320
https://itholic.github.io/python-reverse-string/
- 얕은 복사 : 같은 주소씀 => 복사본과 서로 영향
- 깊은 복사 : 새로운 객체 만듬
- 1차원 배열 90도 회전 알고리즘 https://shoark7.github.io/programming/algorithm/5-ways-to-rotate-array.html
- 2차원 배열 90도 회전 알고리즘 https://shoark7.github.io/programming/algorithm/rotate-2d-array