Leetcode Solutions

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  [Solved] You are given an integer n and an integer start. Define an array nums where nums[i] = start + 2 * i (0-indexed) and n == nums.length. Return the bitwise XOR of all elements of nums.

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  [Solved] Given an array nums. We define a running sum of an array as runningSum[i] = sum(nums[0]…nums[i]). Return the running sum of nums.

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  [Solved] Given two integer arrays startTime and endTime and given an integer queryTime. The ith student started doing their homework at the time startTime[i] and finished it at time endTime[i].

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  [Solved] Given a binary tree root, a node X in the tree is named good if in the path from root to X there are no nodes with a value greater than X. Return the number of good nodes in the binary tree.

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  [Solved] The power of the string is the maximum length of a non-empty substring that contains only one unique character. Given a string s, return the power of s.

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  [Solved] You are given the array paths, where paths[i] = [cityAi, cityBi] means there exists a direct path going from cityAi to cityBi. Return the destination city, that is, the city without any path outgoing to another city.

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  [Solved] There are n kids with candies. You are given an integer array candies, where each candies[i] represents the number of candies the ith kid has, and an integer extraCandies, denoting the number of extra candies that you have.

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  [Solved] Given a string s of zeros and ones, return the maximum score after splitting the string into two non-empty substrings (i.e. left substring and right substring).

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  [Solved] You are given an alphanumeric string s. (Alphanumeric string is a string consisting of lowercase English letters and digits). You have to find a permutation of the string where no letter is followed by another letter and no digit is followed by another digit. That is, no two adjacent characters have the same type.

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  [Solved] Given an integer k, return the minimum number of Fibonacci numbers whose sum is equal to k. The same Fibonacci number can be used multiple times.

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  [Solved] Given an array of integers nums, you start with an initial positive value startValue. In each iteration, you calculate the step by step sum of startValue plus elements in nums (from left to right).

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  [Solved] Given an array of string words. Return all strings in words which is substring of another word in any order. String words[i] is substring of words[j], if can be obtained removing some characters to left and/or right side of words[j].

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  [Solved] Given an array of integers arr, a lucky integer is an integer that has a frequency in the array equal to its value. Return the largest lucky integer in the array. If there is no lucky integer return -1.

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  [Solved] Given two arrays of integers nums and index. Your task is to create target array under the following rules: Initially target array is empty. From left to right read nums[i] and index[i], insert at index index[i] the value nums[i] in target array.

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  [Solved] The power of an integer x is defined as the number of steps needed to transform x into 1 using the following steps: if x is even then x = x / 2

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  [Solved] Given two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays.

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  [Solved] Given an m x n matrix of distinct numbers, return all lucky numbers in the matrix in any order. A lucky number is an element of the matrix such that it is the minimum element in its row and maximum in its column.

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  [Solved] Given two binary trees original and cloned and given a reference to a node target in the original tree. The cloned tree is a copy of the original tree.

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  [Solved] Given an integer n, return a string with n characters such that each character in such string occurs an odd number of times. The returned string must contain only lowercase English letters. If there are multiples valid strings, return any of them.  

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  [Solved] Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to count the number of valid j’s such that j != i and nums[j] < nums[i]. Return the answer in an array.