DescriptionGiven inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. The original problem is here. The original code is

DescriptionGiven preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. The original problem is here. The original code is h

DescriptionGiven a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, …) which sum to n. For example, given n = 12, return 3 because 12 = 4 + 4 + 4; given n

DescriptionGiven a string containing just the characters ‘(‘ and ‘)’, find the length of the longest valid (well-formed) parentheses substring. For “(()”, the longest valid parentheses substring is “(

DescriptionYou are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed b

DescriptionThere are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is express

DescriptionGiven a string of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. The valid operators are +, - and *. Examp

DescriptionWrite a program to find the n-th ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 is the sequence of the

DescriptionGiven two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.) You have the following 3 operations permitted on

DescriptionGiven an absolute path for a file (Unix-style), simplify it. For example,path = “/home/“, => “/home”path = “/a/./b/../../c/“, => “/c” The original problem is here. The original code i