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LeetCode ：single-number

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node./** * Definition for binary tree * stru

Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have the same value./** * Definition

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. 需要两重循环，第一重循环遍历起始点a，第二重循环遍历剩余点b。 a和b如果不重合，就可以确定一条直线。 对于每个点a，构建 斜率->点数 的map。 (1)b与a重合，以a起始的所有

Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and

Related to question Excel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column number.For example:A -> 1B -> 2C -> 3...Z -> 26AA -> 27AB -> 28 clas

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, t

链接：https://www.nowcoder.com/practice/2b7995aa4f7949d99674d975489cb7da?tpId=46&tqId=29060&tPage=1&rp=1&ru=/ta/leetcode&qru=/ta/leetcode/question-ranking 来源：牛客网Given a triangle, find the minimum path su

链接：https://www.nowcoder.com/practice/32139c198be041feb3bb2ea8bc4dbb01?tpId=46&tqId=29126&tPage=1&rp=1&ru=/ta/leetcode&qru=/ta/leetcode/question-ranking 来源：牛客网题目描述Find the contiguous subarray within an

链接：https://www.nowcoder.com/practice/32139c198be041feb3bb2ea8bc4dbb01?tpId=46&tqId=29126&tPage=1&rp=1&ru=/ta/leetcode&qru=/ta/leetcode/question-ranking 来源：牛客网题目描述Find the contiguous subarray within an

Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical and the nodes have the same value./** * Definition f

链接：https://www.nowcoder.com/practice/1025ffc2939547e39e8a38a955de1dd3?tpId=46&tqId=29048&tPage=1&rp=1&ru=/ta/leetcode&qru=/ta/leetcode/question-ranking 来源：牛客网题目描述Given a string s, partition s such tha

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.You may assume that the array is non-empty and the majority element always

Total Accepted: 32005 Total Submissions: 45111 Difficulty: Easy Contributors: Samuri The Hamming distance between two integers is the number of positions at which the corresponding bits are different.

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.Note: The given integer is guaranteed to fit within the range of a 32-b

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.Note: The given integer is guaranteed to fit within the range of a 32-b

Given a List of words, return the words that can be typed using letters of alphabet on only one row’s of American keyboard like the image below.American keyboardExample 1: Input: [“Hello”, “Alaska”, “

Given two strings s and t, write a function to determine if t is an anagram of s.For example, s = “anagram”, t = “nagaram”, return true. s = “rat”, t = “car”, return false.Note: You may assume the s

You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1’s elements in the corresponding places of nums2.The

Write a program that outputs the string representation of numbers from 1 to n.But for multiples of three it should output “Fizz” instead of the number and for the multiples of five output “Buzz”. For n

Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.This is case sensitive, for example “Aa” is not consider

You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely s

Given a word, you need to judge whether the usage of capitals in it is right or not.We define the usage of capitals in a word to be right when one of the following cases holds:All letters in this word

Given a binary array, find the maximum number of consecutive 1s in this array.Example 1: Input: [1,1,0,1,1,1] Output: 3 Explanation: The first two digits or the last three digits are consecutive 1s.

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 stone will be the

Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once.Find all the elements of [1, n] inclusive that do not appear in this array.Could you

Given an array of integers, every element appears twice except for one. Find that single one.Note: Your algorithm should have a linear runtime complexity. Could you implement it without using extra me

Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.Subscribe to see which companies asked this

//特别注意，这一题是关于位运算的典型问题 思想是分别处理相同位和不同位的二进制数，使用& 和 ^两个操作&得到的结果是除以2后得到 ^得到的则无需处理 Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.Example: Given a = 1 and

Given 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 was added in

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. Since 2 has only one digit, r

Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is

Invert a binary tree. 4/ \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia: This problem was inspired by this original tweet by Max Howell: Go

Total Accepted: 133406 Total Submissions: 301893 Difficulty: Easy Contributors: Admin Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.class

For a web developer, it is very important to know how to design a web page’s size. So, given a specific rectangular web page’s area, your job by now is to design a rectangular web page, whose length L

Given scores of N athletes, find their relative ranks and the people with the top three highest scores, who will be awarded medals: “Gold Medal”, “Silver Medal” and “Bronze Medal”.Example 1: Input: [5

Given 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.For example, given nums = [0, 1, 0, 3, 12], after calling your funct

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers suc

Given two arrays, write a function to compute their intersection.Example: Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2].Note: Each element in the result should appear as many times as it

Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie. Each child i has a greed factor gi, which is the minimum size of a cook