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

摘要： There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following re 阅读全文

摘要： Implement int sqrt(int x). Compute and return the square root of x. 注意: 计算平方的时候可能会溢出，所以mid要定义为long 另外，二分法初始上限不可能超过n/2+1 阅读全文

摘要： Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST. 也可以通过引用传递，这样就不需要先初始化。 注意，NULL是一个宏定义 #def 阅读全文

摘要： Given an array where elements are sorted in ascending order, convert it to a height balanced BST.思路：使用二分法，将list的中间节点作为根节点，然后分别处理list左半边及右半边，以此递归。struc... 阅读全文

摘要： Given a sorted array of integers, find the starting and ending position of a given target value. Your algorithm's runtime complexity must be in the or 阅读全文

摘要： Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in or 阅读全文

摘要： Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list. For example,Given 1->2... 阅读全文

摘要： Given a sorted linked list, delete all duplicates such that each element appear only once. For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3,... 阅读全文

摘要： Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array nums = [1,1,1,2,2,3], Your function s 阅读全文

摘要： Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…You must do this in-place without altering the nodes' values.For ... 阅读全文

摘要： Given a list, rotate the list to the right by k places, where k is non-negative.For example:Given 1->2->3->4->5->NULL and k = 2,return 4->5->1->2->3->... 阅读全文

摘要： Reverse a linked list from position m to n. Do it in-place and in one-pass. For example: Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2 阅读全文

摘要： Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.You should preserve the o... 阅读全文

摘要： Sort a linked list in O(n log n) time using constant space complexity. 法I：快排。快排的难点在于切分序列。从头扫描，碰到>=target的元素，停止；从第二个字串扫描，碰到<=target的元素停止；交换这两个元素。这样的好处是 阅读全文

摘要： Sort a linked list using insertion sort. 阅读全文

摘要： Given an unsorted array of integers, find the length of the longest consecutive elements sequence. For example, Given [100, 4, 200, 1, 3, 2], The long 阅读全文

摘要： Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, ... 阅读全文

摘要： Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note:You may assume that nums1 has enough space (size tha... 阅读全文