摘要：
Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as: a binary tree in which the dep 阅读全文
摘要：
You are asked to cut off trees in a forest for a golf event. The forest is represented as a non-negative 2D map, in this map: You are asked to cut off 阅读全文
摘要：
The Fibonacci numbers are the numbers in the following integer sequence. 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …….. In mathematical terms, the 阅读全文