摘要:
Given a positive integer num, write a function which returns True if num is a perfect square else False. Note: Do not use any built-in library functio 阅读全文
摘要:
Given a binary tree, collect a tree's nodes as if you were doing this: Collect and remove all leaves, repeat until the tree is empty. Example:Given bi 阅读全文
摘要:
Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: A = [ [ 1, 0, 0 阅读全文