北叶青藤

摘要： Given an unsorted array return whether an increasing subsequence of length 3 exists or not in the array. Formally the function should: Return true if 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 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 form 阅读全文

摘要： An image is represented by a binary matrix with 0 as a white pixel and 1 as a black pixel. The black pixels are connected, i.e., there is only one bla 阅读全文

摘要： Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges mak 阅读全文

摘要： There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have t 阅读全文

摘要： Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. 阅读全文

摘要： Strobogrammatic Number I A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down). Write a function t 阅读全文

摘要： You are given a m x n 2D grid initialized with these three possible values. -1 - A wall or an obstacle. 0 - A gate. INF - Infinity means an empty room 阅读全文

摘要： Contains Duplicate I Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at l 阅读全文