拉凯斯Laches

LeetCode 1884 Egg Drop With 2 Eggs and N Floors 链接：https://leetcode.com/problems/egg-drop-with-2-egg

LeetCode 230 Kth Smallest Element in a BST 链接：https://leetcode.com/problems/kth-smallest-element-in-

LeetCode 348, 285 LeetCode 348 Design Tic-Tac-Toe 链接：https://leetcode.com/problems/design-tic-tac-to

LeetCode 37 Sudoku Solver 链接：https://leetcode.com/problems/sudoku-solver/ 方法1：普通DFS 想法：这个题反正填数独肯定是暴搜

LeetCode 153, 154 Find Minimum in Rotated Sorted Array I & II

今天写二叉树的三种遍历，分别用递归，迭代和Morris遍历。按理来说是9种，但是后序遍历用Morris遍历先不写了。 LeetCode 144 Bin

LeetCode 236 Lowest Common Ancestor of a Binary Tree 链接：https://leetcode.com/problems/lowest-common-

LeetCode 251 Flatten 2D Vector 链接：https://leetcode.com/problems/flatten-2d-vector/ 方法：双指针 时间复杂度：O(n)

LeetCode 269 Alien Dictionary 链接：https://leetcode.com/problems/alien-dictionary/ 方法：拓扑排序BFS 时间复杂度：O(