摘要：
Design a Phone Directory which supports the following operations: Example: Analysis: We record the last used number and also maintain a hashset to rec 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
摘要：
Given a sorted positive integer array nums and an integer n, add/patch elements to the array such that any number in range [1, n] inclusive can be for 阅读全文