2017年7月16日
108. Convert Sorted Array to Binary Search Tree
摘要： Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 阅读全文
posted @ 2017-07-16 22:59 白天黑夜每日c 阅读(93) 评论(0) 推荐(0) 编辑
99. Recover Binary Search Tree
摘要： Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Note: A solution using O(n) space 阅读全文
posted @ 2017-07-16 22:46 白天黑夜每日c 阅读(127) 评论(0) 推荐(0) 编辑
94. Binary Tree Inorder Traversal
摘要： Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree [1,null,2,3], 1 \ 2 / 3 return [1,3,2]. Note: Re 阅读全文
posted @ 2017-07-16 22:23 白天黑夜每日c 阅读(131) 评论(0) 推荐(0) 编辑
235. Lowest Common Ancestor of a Binary Search Tree
摘要： Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST. According to the definition of LCA on Wikipedia 阅读全文
posted @ 2017-07-16 21:48 白天黑夜每日c 阅读(141) 评论(0) 推荐(0) 编辑
96. Unique Binary Search Trees
摘要： Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST' 阅读全文
posted @ 2017-07-16 21:48 白天黑夜每日c 阅读(111) 评论(0) 推荐(0) 编辑
226. Invert Binary Tree
摘要： Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia:This problem was inspired by this original tweet by Max Howell: Go 阅读全文
posted @ 2017-07-16 21:47 白天黑夜每日c 阅读(132) 评论(0) 推荐(0) 编辑
2017年7月14日
232. Implement Queue using Stacks
摘要： Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front 阅读全文
posted @ 2017-07-14 23:00 白天黑夜每日c 阅读(106) 评论(0) 推荐(0) 编辑
155. Min Stack
摘要： Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) -- Push element x onto stack. pop() -- Remov 阅读全文
posted @ 2017-07-14 12:12 白天黑夜每日c 阅读(124) 评论(0) 推荐(0) 编辑
316. Remove Duplicate Letters
摘要： Given a string which contains only lowercase letters, remove duplicate letters so that every letter appear once and only once. You must make sure your 阅读全文
posted @ 2017-07-14 12:11 白天黑夜每日c 阅读(390) 评论(0) 推荐(0) 编辑
20. Valid Parentheses
摘要： Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the 阅读全文
posted @ 2017-07-14 12:11 白天黑夜每日c 阅读(133) 评论(0) 推荐(0) 编辑