December 2018

Link: https://leetcode.com/problems/flip-equivalent-binary-trees/  Thought If 2 nodes are equivalent, either their left and right side match, or they are flipped match. So […]

link: https://leetcode.com/problems/reveal-cards-in-increasing-order/ Thought So the rule is if you pop anything from front, then you shall move next head to tail.

link: https://leetcode.com/problems/largest-time-for-given-digits/ Thought Its easy to think use DFS to solve it: it has limit data(4 digits), and DFS will enumerates