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Given an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution, and you may not use the same ...

Implementnext permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangement is not possible, it must rearrange it as the lowest possible o...

38.Count and SayThe count-and-say sequence is the sequence of integers with the first five terms as following:1. 12. 113. 214. 12115. 1112211is read off as"one 1"or...

Given asetof candidate numbers (candidates)(without duplicates)and a target number (target), find all unique combinations incandidateswhere the candidate numbers sums totarget.Thesamerepeat...

Given an array of strings, group anagrams together.Example:Input: ["eat", "tea", "tan", "ate", "nat", "bat"],Output:[ ["ate","eat","tea"], ["nat"

Given an integer arraynums, find the contiguous subarray(containing at least one number) which has the largest sum and return its sum.Example:Input: [-2,1,-3,4,-1,2,1,-5,4],Output: 6Explanati...

Implementpow(x,n), which calculatesxraised to the powern(xn).Example 1:Input: 2.00000, 10Output: 1024.00000Example 2:Input: 2.10000, 3Output: 9.26100Example 3:Input: 2.00000, ...

Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations incandidateswhere the candidate numbers sums totarget.Each number incandidatesmay...

A robot is located at the top-left corner of amxngrid (marked 'Start' in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the bo...

Givennnon-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.The above elevation map is represented by array...

Then-queens puzzle is the problem of placingnqueens on ann×nchessboard such that no two queens attack each other.Given an integern, return all distinct solutions to then-queens puzzle.Eac...

Given an array of words and a widthmaxWidth, format the text such that each line has exactlymaxWidthcharacters and is fully (left and right) justified.You should pack your words in a greedy appro...

Given a matrix ofmxnelements (mrows,ncolumns), return all elements of the matrix in spiral order.Example 1:Input:[ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ]]Output: [1,2,3,6,9,8,7,4,5]...

Implementint sqrt(int x).Compute and return the square root ofx, wherexis guaranteed to be a non-negative integer.Since the return typeis an integer, the decimal digits are truncated and only...

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Determine if yo...

The set[1,2,3,...,n]contains a total ofn! unique permutations.By listing and labeling all of the permutations in order, we get the following sequence forn= 3:"123" "132" "213" "231" "312"...

Given a collection of intervals, merge all overlapping intervals.Example 1:Input: [[1,3],[2,6],[8,10],[15,18]]Output: [[1,6],[8,10],[15,18]]Explanation: Since intervals [1,3] and [2,6] overlaps...

You are climbing a stair case. It takesnsteps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?Note:Givennwill be a positive...

Given a linkedlist, rotate the list to the right bykplaces, wherekis non-negative.Example 1:Input: 1->2->3->4->5->NULL, k = 2Output: 4->5->1->2->3->NULLExplana...

Given an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.Your goal is to...

Given a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically n...

Given a set ofnon-overlappingintervals, insert a new interval into the intervals (merge if necessary).You may assume that the intervals were initially sorted according to their start times.Examp...

A robot is located at the top-left corner of amxngrid (marked 'Start' in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the bo...

Given amxngrid filled with non-negative numbers, find a path from top left to bottom right whichminimizesthe sum of all numbers along its path.Note:You can only move either down or right at a...

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving onlydistinctnumbers from the original list.Example 1:Input: 1->2->3->3->4->4->5Output: 1-&gt...

Given a sorted linked list, delete all duplicates such that each element appear onlyonce.Example 1:Input: 1->1->2Output: 1->2Example 2:Input: 1->1->2->3->3Output: 1-...

Given a string containing only digits, restore it by returning all possible valid IP address combinations.Example:Input: "25525511135"Output: ["255.255.11.135", "255.255.111.35"]题目大意：给出一个st...

Given two wordsword1andword2, find the minimum number of operations required to convertword1toword2.You have the following 3 operations permitted on a word:Insert a character Delete a chara...

Given anon-emptyarray of digitsrepresenting a non-negative integer, plus one to the integer.The digits are stored such that the most significant digit is at the head of the list, and each element...

Givennnon-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.Above is a histogram where width of ea...

Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing only 1's and return its area.Example:Input:[ ["1","0","1","0","0"], ["1","0","1","1","1"], ["1","1",...

Given two binary strings, return their sum (also a binary string).The input strings are bothnon-emptyand contains only characters1or0.Example 1:Input: a = "11", b = "1"Output: "100"Exam...

Given a linked list and a valuex, partition it such that all nodes less thanxcome before nodes greater than or equal tox.You should preserve the original relative order of the nodes in each of th...

Given a binary tree, return theinordertraversal of its nodes' values.Example:Input: [1,null,2,3] 1 \ 2 / 3Output: [1,3,2]题目大意：二叉树中序遍历。解题思路：按照左输出右的递归即可。/** * ...

Given a strings1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible representation ofs1="great": great / \ gr ...

Given two sorted integer arraysnums1andnums2, mergenums2intonums1as one sorted array.Note:The number of elements initialized innums1andnums2aremandnrespectively. You may assume that...

The gray code is a binary numeral system where two successive values differ in only one bit.Given a non-negative integernrepresenting the total number of bits in the code, print the sequence of gr...

Given a binary tree, return thelevel ordertraversal of its nodes' values. (ie, from left to right, level by level).For example:Given binary tree[3,9,20,null,null,15,7], 3 / \ 9 20 ...

Given an integern, generate all structurally uniqueBST's(binary search trees) that store values 1 ...n.Example:Input: 3Output:[ [1,null,3,2], [3,2,null,1], [3,1,null,null,2], [2,1,3...

Given a collection of integers that might contain duplicates,nums, return all possible subsets (the power set).Note:The solution set must not contain duplicate subsets.Example:Input: [1,2,2]...