Xylophone - 博客园

2014年8月6日

Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2.For example, Given: s1 = "aabcc", s2 = "dbbca",When s3 = "aadbbcbcac", re... Read More

posted @ 2014-08-06 20:39 Xylophone Views(114) Comments(0) Diggs(0) Edit

[LeetCode] Validate Binary Search Tree

Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only n... Read More

posted @ 2014-08-06 11:04 Xylophone Views(101) Comments(0) Diggs(0) Edit

[LeetCode] Recover Binary Search Tree

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 is... Read More

posted @ 2014-08-06 10:39 Xylophone Views(162) Comments(0) Diggs(0) Edit

2014年8月5日

[LeetCode] Restore IP Addresses

Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example: Given "25525511135",return ["25... Read More

posted @ 2014-08-05 17:30 Xylophone Views(152) Comments(0) Diggs(0) Edit

[LeetCode] Unique Paths II(DP)

Follow up for "Unique Paths":Now consider if some obstacles are added to the grids. How many unique paths would there be?An obstacle and empty space i... Read More

posted @ 2014-08-05 15:36 Xylophone Views(114) Comments(0) Diggs(0) Edit

2014年8月4日

[LeetCode] Remove Duplicates from Sorted Array II

Follow up for "Remove Duplicates": What if duplicates are allowed at most twice?For example, Given sorted array A = [1,1,1,2,2,3],Your function should... Read More

posted @ 2014-08-04 22:40 Xylophone Views(143) Comments(0) Diggs(0) Edit

[LeetCode] Binary Tree Zigzag Level Order Traversal（bfs）

Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and ... Read More

posted @ 2014-08-04 22:00 Xylophone Views(173) Comments(0) Diggs(0) Edit

[LeetCode] Construct Binary Tree from Preorder and Inorder Traversal

Given preorder and inorder traversal of a tree, construct the binary tree.Note: You may assume that duplicates do not exist in the tree./** * Definiti... Read More

posted @ 2014-08-04 21:11 Xylophone Views(141) Comments(0) Diggs(0) Edit

[LeetCode] Construct Binary Tree from Inorder and Postorder Traversal

Given inorder and postorder traversal of a tree, construct the binary tree.Note: You may assume that duplicates do not exist in the tree.class Solutio... Read More

posted @ 2014-08-04 20:58 Xylophone Views(155) Comments(0) Diggs(0) Edit

[LeetCode] Convert Sorted List to Binary Search Tree（分治）

Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.方法：为了使BST高度平衡，要找链表中的中值作为当前根节点。/** * Defin... Read More

posted @ 2014-08-04 16:59 Xylophone Views(156) Comments(0) Diggs(0) Edit