随笔分类 - Great Questions
摘要：Given n, how many structurally unique BSTs (binary search trees) that store values 1...n? Given n, how many structurally unique BSTs (binary search tr
阅读全文
摘要：Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only
阅读全文
摘要：Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. Example Given the below binary tree: 1 / \ 2 3 ret
阅读全文
摘要：Given two strings, find the longest common subsequence (LCS). Your code should return the length of LCS. Example For "ABCD" and "EDCA", the LCS is "A"
阅读全文
摘要：Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example Given lists: [ 2->4->null, null, -1->null ]
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
摘要：Ugly Number Write a program to check whether a given number is an ugly number`. Ugly numbers are positive numbers whose prime factors only include 2,
阅读全文
摘要：For an array A, if i < j, and A [i] > A [j], called (A [i], A [j]) is a reverse pair.return total of reverse pairs in A. For an array A, if i < j, and
阅读全文
摘要：Swap Nodes | Given a linked list, swap every two adjacent nodes and return its head. Example Given 1->2->3->4, you should return the list as 2->1->4->
阅读全文
摘要：Best Time to Buy and Sell Stock I Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted t
阅读全文
摘要：There are two sorted arrays A and B of size m and nrespectively. Find the median of the two sorted arrays. There are two sorted arrays A and B of size
阅读全文
摘要：Design an algorithm and write code to serialize and deserialize a binary tree. Writing the tree to a file is called 'serialization' and reading back f
阅读全文
摘要：Jump Game | Given an array of non-negative integers, you are initially positioned at the first index of the array. Each element in the array represent
阅读全文
摘要：Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Clarification Your algorithm should run in O(n) com
阅读全文
摘要：k Sum Given n distinct positive integers, integer k (k <= n) and a number target. Find k numbers where sum is target. Calculate how many solutions the
阅读全文
摘要：Single Number Given 2*n + 1 numbers, every numbers occurs twice except one, find it. Example Given [1,2,2,1,3,4,3], return 4 分析： 利用bit operator ^ 的特点即
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 a collection of distinct numbers, return all possible permutations. For example,[1,2,3] have the following permutations: [ [1,2,3], [1,3,2], [2,
阅读全文
摘要：Given a linked list, determine if it has a cycle in it. Given a linked list, determine if it has a cycle in it. Given a linked list, determine if it h
阅读全文
摘要：Sort a linked list in O(n log n) time using constant space complexity. Example Given 1->3->2->null, sort it to 1->2->3->null. Merge Sort version 1 /**
阅读全文
浙公网安备 33010602011771号