摘要： Solution: 1. From left to right 阅读全文

摘要： Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) Yo 阅读全文

摘要： A matrix is Toeplitz if every diagonal from top-left to bottom-right has the same element. Now given an M x N matrix, return True if and only if the m 阅读全文

摘要： Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element 阅读全文

摘要： Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: Input: 3 / \ 9 20 / \ 15 7 Outp 阅读全文

摘要： Given two binary trees and imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are n 阅读全文

摘要： Given m arrays, and each array is sorted in ascending order. Now you can pick up two integers from two different arrays (each array picks one) and cal 阅读全文

摘要： Given a list of positive integers, the adjacent integers will perform the float division. For example, [2,3,4] -> 2 / 3 / 4. However, you can add any 阅读全文

摘要： Suppose you have a long flowerbed in which some of the plots are planted and some are not. However, flowers cannot be planted in adjacent plots - they 阅读全文

摘要： You need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way. The null node needs to be rep 阅读全文