Category Leetcode Solutions

Question 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). Return the minimum positive value of startValue such that the step by step sum is never less than…

Question 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]. Example 1: Input: words = [“mass”,”as”,”hero”,”superhero”] Output: [“as”,”hero”] Explanation: “as”…

Question 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. Example 1: Input: arr = [2,2,3,4] Output: 2 Explanation:…

Question 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. Repeat the previous step until there are no elements to…

Question 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 if x is odd then x = 3 * x + 1 For example, the power of x =…

Question Given two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays. The distance value is defined as the number of elements arr1[i] such that there is not any element arr2[j] where |arr1[i]-arr2[j]| <= d. Example 1: Input: arr1 = [4,5,8], arr2…

Question 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. Example 1: Input: matrix = [[3,7,8],[9,11,13],[15,16,17]] Output:…

Question 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. Return a reference to the same node in the cloned tree. Note that you are not allowed to change any of the two trees or the target node and the answer must…

Question 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.   Example 1: Input: n…

Question 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. Example…