摘要： Implement a trie with insert, search, and startsWith methods. Note: You may assume that all inputs are consist of lowercase letters a-z. 终于进军trie树，tri 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： Given an array of integers and a number k, find k non-overlapping subarrays which have the largest sum. The number in each subarray should be contiguo 阅读全文

摘要： Given an array of integers, find two non-overlapping subarrays which have the largest sum. The number in each subarray should be contiguous. Return th 阅读全文

摘要： Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2, 阅读全文

摘要： Given an integer array, adjust each integers so that the difference of every adjacent integers are not greater than a given number target. If the arra 阅读全文

摘要： Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array whic 阅读全文

摘要： Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. 阅读全文

摘要： Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of 阅读全文

摘要： The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other. Given an integer n, return all 阅读全文