摘要：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 阅读全文

摘要：Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).For example:Given binary tree [3, 阅读全文

摘要：Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical an 阅读全文

摘要：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 阅读全文

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 / 3return [1,3,2].Note: Recur 阅读全文

摘要：Follow up for "Search in Rotated Sorted Array":What if duplicates are allowed?Would this affect the run-time complexity? How and why?Write a function 阅读全文

摘要：Given an array of words and a length L, format the text such that each line has exactly L characters and is fully (left and right) justified.You shoul 阅读全文