https://www.bilibili.com/video/av96214853/
举一反三:
规律竟然是观察出来的,并不是计算,理解,技巧 想出来的,怎么想也想不不明白
https://chanjarster.github.io/post/cracking-coding-interview/a001-put-apples/
https://www.nowcoder.com/questionTerminal/a2a1d0266629404fba582d416d84b6a0
https://www.bilibili.com/video/av370226643/