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QuestionGiven a list of unique words, find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome.Example 1:Inp...

QuestionYou are given an integer array nums and you have to return a new counts array. The counts array has the property where counts[i] is the number of smaller elements to the right of nums[i].Exa...

Question743. Network Delay TimeThere are N network nodes, labelled 1 to N.Given times, a list of travel times as directed edges times[i] = (u, v, w), where u is the source node, v is the target nod...

Given two binary trees and imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not.You need to merge them into a new binary tree....

QuestionGiven a non-negative integer represented as non-empty a singly linked list of digits, plus one to the integer.You may assume the integer do not contain any leading zero, except the number 0 ...

QuestionGiven the coordinates of four points in 2D space, return whether the four points could construct a square.The coordinate (x,y) of a point is represented by an integer array with two integers...

QuestionGiven an array nums, write a function to move all 0’s to the end of it while maintaining the relative order of the non-zero elements.Example:Input: [0,1,0,3,12]Output: [1,3,12,0,0]Algori...

QuestionGiven a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.Example 1:Input: "Let's take LeetCode con...

QuestionSuppose we have a class:public class Foo { public void first() { print("first"); } public void second() { print("second"); } public void third() { print("third"); }}The same instanc...

QuestionGiven two strings s and t which consist of only lowercase letters.String t is generated by random shuffling string s and then add one more letter at a random position.Find the letter that w...

Question：You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last st

Question：Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.For example:Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. S

Question：Write a function that takes a string as input and returns the string reversed.Example:Given s = "hello", return "olleh".算法：（1）复制一个字符串  （2）逆序给原来的字符串class Solution {public:

Question:Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.Do not allocate extra space for another array, you must do this in place...

Question：Determine whether an integer is a palindrome. Do this without extra space.判断一个整数是否为回文数，回文数是把整数n的各位数字反向排列所得数与n相等。Algorithm：把n的各位数字反向排列得到的数和n相等即是回文数Submitted Code：class Soluti

Question：Given a range [m, n] where 0 For example, given the range [5, 7], you should return 4.即把在 m Algorithm：Bit Manipulation我们不妨先举几个例子：1、m=5(1001),n=5(1001);m-n=0 return 5(1

前言：先说点背景吧，这题我一直放着没做，因为我不知道Roman数是怎么计数的呀，然后最近在看《数学之美》（特别有意思的书，第一次觉得数学还挺有意思的）罗马人也是用不同的符号代表数的不同量级。Symbol  ValueI                  1V                 5X                10L             

Question：Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.The same repeated number may be chosen from C u

Question:Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums toT.Each number in C may only be used once 

Question：You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return

Question：Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring.题目大意是找出

Question：The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H

Question:Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) an

Question：Given a linked list, remove the nth node from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from

Question：Implement atoi to convert a string to an integer.Hint: Carefully consider all possible input cases. If you want a challenge, please do not see below and ask yourself what are the poss

Question:Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:[ "((()))", "(()())", "(())(

Question:Given a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2->1->4->3.Your algorithm should use only cons

Question:Given an array and a value, remove all instances of that value in place and return the new length.Do not allocate extra space for another array, you must do this in place with constan

Question: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 distinct solutions to the n-qu

Question：Write a program to solve a Sudoku puzzle by filling the empty cells.Empty cells are indicated by the character '.'.You may assume that there will be only one unique solution.A sud

Question：Implement strStr().Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.题目大意就是在字符串haystack中有没有字符串needle，如果有返回下标，如果没有返回-1Alg

Question:Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.题目大意就是不用乘法算两个数相除的结果Algorithm:用语言描述有点说不清楚。。。。举个例子，65/9=(36

Question:Given an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999.

Question：Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicate

Question:Implement pow(x, n).Algorithm:举个例子：假如是3的35次方，35=2^5+2^1+2^0,要注意超出INT_MAX的情况Accepted Code:class Solution {public: double myPow(double x, int n) { if(n==0)return 1;

Question: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,−1,2,1,−5,4],the contiguous subarray

Question：Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

Question：Write a function to find the longest common prefix string amongst an array of strings.大意即是求字符串组的最长公共前缀Ex：vector strs={"abc","abcd","abcdef"};那么最长公共前缀即"abc";Algorithm：先找出最小长度的字符串长度

Question: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 zero.Note: The solution set mus

Question: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. You may assume that each input wou