摘要： Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring.For "(()", the lon... 阅读全文

摘要： Given an absolute path for a file (Unix-style), simplify it. For example, path = "/home/", => "/home" path = "/a/./b/../../c/", => "/c" 注意：题目中已限定是abso 阅读全文

摘要： 1. Array & List 1.1Sort Array的变更操作，好好运用尾指针：88题的end，75题的blueHead 88. Merge Sorted Array (Array) 75. Sort Colors 21. Merge Two Sorted Lists 23. Merge k 阅读全文

摘要： Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, return [3,2,1]. Note: Recursive so 阅读全文

摘要： Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3return [1,2,3... 阅读全文

摘要： Given a binary tree, flatten it to a linked list in-place. For example, Given The flattened tree should look like: 法I：递归，前序遍历 法II：迭代 每次循环，找到左子树前序遍历的最后 阅读全文

摘要： Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the 阅读全文

摘要： Given a linked list, return the node where the cycle begins. If there is no cycle, return null.Note: Do not modify the linked list. Follow up:Can you ... 阅读全文

摘要： Given a linked list, determine if it has a cycle in it. Follow up:Can you solve it without using extra space?思路：采用“快慢指针”查检查链表是否含有环。让一个指针一次走一步，另一个一次走两步... 阅读全文

摘要： Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"A man, a plan, a canal: Pan... 阅读全文