摘要：
Given a binary tree, return all root-to-leaf paths. Note: A leaf is a node with no children. Example: Approach #1: C++. [recursive] Approach #2: Java. 阅读全文
摘要：
The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each hou 阅读全文
摘要：
Given a list of airline tickets represented by pairs of departure and arrival airports [from, to], reconstruct the itinerary in order. All of the tick 阅读全文
摘要：
Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or do 阅读全文