MoM

This is a follow up of Shortest Word Distance. The only difference is now you are given the list of words and your method will be called repeatedly many times with different parameters. How would you o

今天开始先把leetcode收费题思路整理到这里，因为只买了一个月。。。＝＝， 用中文吗。Binary Tree Upside Down My Submissions QuestionTotal Accepted: 6016 Total Submissions: 16909 Difficulty: MediumGiven a binary tree where all the right nod

Given two sparse matrices A and B, return the result of AB.You may assume that A's column number is equal to B's row number.Example: A = [ [ 1, 0, 0], [-1, 0, 3] ] B = [ [ 7

Hard ..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 black region. Pixels are connected horizontally

Given a binary tree, find the length of the longest consecutive sequence path.The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections

EasyYou are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you and your friend take turns to flip two consecutive "++" into "--". The

Hard..A 2d grid map of m rows and n columns is initially filled with water. We may perform an addLand operation which turns the water at position (row, col) into a land. Given a list of positions to op

An abbreviation of a word follows the form <first letter><number><last letter>. Below are some examples of word abbreviations:a) it --> it (no abbreviation) 1b) d|o|g

Given a binary search tree and a node in it, find the in-order successor of that node in the BST.Note: If the given node has no in-order successor in the tree, return null.Hide Tags TreeHide Similar P

Suppose you are at a party with n people (labeled from 0 to n - 1) and among them, there may exist one celebrity. The definition of a celebrity is that all the other n - 1 people know him/her but he/sh

Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target.Note:Given target value is a floating point.You may assume k is always valid, that is:

Given two 1d vectors, implement an iterator to return their elements alternately.For example, given two 1d vectors:v1 = [1, 2]v2 = [3, 4, 5, 6]By calling next repeatedly until hasNext returns false,

Given an unsorted array nums, reorder it in-place such that nums[0] <= nums[1] >= nums[2] <= nums[3]....For example, given nums = [3, 5, 2, 1, 6, 4], one possible answer is [1, 6, 2, 5, 3, 4].Hide Comp

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2).Range Sum Query 2DThe above rectangle (wit

Given a pattern and a string str, find if str follows the same pattern.Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty substring in str.Exampl

Given an array nums and a target value k, find the maximum length of a subarray that sums to k. If there isn't one, return 0 instead.Example 1:Given nums = [1, -1, 5, -2, 3], k = 3,return 4. (because

Given a binary tree, return the vertical order traversal of its nodes' values. (ie, from top to bottom, column by column).If two nodes are in the same row and column, the order should be from left to r

Given a complete binary tree, count the number of nodes.Definition of a complete binary tree from Wikipedia:In a complete binary tree every level, except possibly the last, is completely filled, and a

HARDGiven a 2D board and a list of words from the dictionary, find all words in the board.Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those hori

Write an algorithm to determine if a number is "happy".A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of i

All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful to identify repeated sequences within the DNA.Write a

Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input string does not contain leading or trailing spaces and the words are always sep

我靠！弄了一个小时！class node{public: int height, size, val; node *left, *right; node(int val){ this->val = val; this->height = 1; this->size = 1; this->left = this-

You want to build a house on an empty land which reaches all buildings in the shortest amount of distance. You are given a 2D grid of values 0, 1 or 2, where:Each 0 marks an empty land which you can pa

HARDGiven an unsorted array, find the maximum difference between the successive elements in its sorted form.Try to solve it in linear time/space.Return 0 if the array contains less than 2 elements.You

A group of two or more people wants to meet and minimize the total travel distance. You are given a 2D grid of values 0 or 1, where each 1 marks the home of someone in the group. The distance is calcul

You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + and -, you and your friend take turns to flip two consecutive "++" into "--". The gam

There is a fence with n posts, each post can be painted with one of the k colors.You have to paint all the posts such that no more than two adjacent fence posts have the same color.Return the total num

Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target.Note: Given target value is a floating point. You are guaranteed to have only on

There are a row of n houses, each house can be painted with one of the k colors. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adj

Design and implement a TwoSum class. It should support the following operations: add and find.add - Add the number to an internal data structure.find - Find if there exists any pair of numbers which s

The API: int read4(char *buf) reads 4 characters at a time from a file.The return value is the actual number of characters read. For example, it returns 3 if there is only 3 characters left in the file

Given a list of words and two words word1 and word2, return the shortest distance between these two words in the list.For example,Assume that words = ["practice", "makes", "perfect", "coding", "makes"

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Write a function to determine if a number is strobogrammatic. The number is represented as a st

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Find all strobogrammatic numbers that are of length = n.For example,Given n = 2, return ["11",

Given two strings S and T, determine if they are both one edit distance apart.Hide Company Tags Uber FacebookHide Tags StringHide Similar Problems (H) Edit Distance所谓Edit distance, 一次delete, insert

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 make up a valid tree.For example:Given n = 5 and edges

Given a string, find the length of the longest substring T that contains at most 2 distinct characters.For example, Given s = “eceba”,T is "ece" which its length is 3.Hide Company Tags GoogleHide Tags

A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Write a function to count the total strobogrammatic numbers that exist in the range of low <= n

This is a follow up of Shortest Word Distance. The only difference is now word1 could be the same as word2.Given a list of words and two words word1 and word2, return the shortest distance between thes