Leetcode

Given an array, find the indices of 2 elements, that have a sum equal to the given target value.

Given two strings str1 and str2. Write a function to determine if str1 is an anagram of str2. Example 1:str1 = “listen”, str2 = “silent”Output = True Example 2:str1 = “mississippi”, str2 = “mips”Output = False Terminology: Anagram: Two words or phrases are said to be anagrams of each other if they can be formed by re-shuffling of characters in one of them. Problem Statement: In the given problem we have 2 strings as input. They may be single words or phrases. Return true if they anagrams of each other,…

You are given a string with some repeating characters and some unique characters. Find the first unique character and return its index. Example 1:Input: studyAlgorithmsOutput: 2 Example 2:Input: iLoveToCodeOutput: 0 Problem Statement: I want to simplify the problem statement first before we begin to solve it. An input string consists of some uppercase and lowercase characters which may or may not be repeated. Out of all the unique characters, you need to return the characters that occurs first in the string. In the first example studyAlgorithms, s, and t are…

You are given 2 sorted linked lists with a head pointer. Find a way to merge these 2 lists and return a single sorted list. Try to solve the problem without using any extra space. Example 1:List 1: 1 -> 2 -> 4List 2: 1 -> 3 -> 4Output: 1 -> 1 -> 2 -> 3 -> 4 -> 4 Problem statement To read about Linked Lists, refer to the post “What is a Linked List“? For our current problem statement, we are given two list heads or we refer…

Let us suppose you are given an array of integers. The special thing about this array is that all numbers are repeated twice except one. Find the single non-repeating number. Example 1:Input: [2, 1, 1]Output: 2 Example 2:Input: [4, 5, 5, 2, 2]Output: 4 Problem statement: You are given an array of all positive integers. All the integers are repeated exactly twice except one. We need to find that number with a linear time complexity and using the minimum space possible. Brute Force Method: When tackling such problems, it is…

Let us suppose that we are given a string ‘str’. You need to find out the longest palindrome as a substring. Note that the elements of the string should be contagious. Example 1:Input: “aaebabad”Output: “bab”Note: “aba” is also a valid answer Example 2:Input: “cbeereed”Output: “eeree” Terminology: Palindrome: A palindrome is a type of string that reads the same when reading left to right and right to left. An example of a palindrome can be “level”, “racecar”, “kayak” etc. Sub-string: A string formed formed using the characters of the string that…