# Coding Interview Study Guide ### Magical usage of Bitwise operators - Get optimized solutions for many arithmatic problems

Introduction I will list some of the interesting usage of bitwise operators, which looks complex on first look. But, if... ### Swap Nodes Pairs in Link List - Leet Code Solution

Problem Statement Given a linked list, swap every two adjacent nodes and return its head. You may not modify the... ### Three Sum - Leet Code Solution

Problem Statement Given an array nums of n integers, are there elements a, b, c in nums such that a... ### Three Sum Closest - Leet Code Solution

Problem Statement Given an array nums of n integers and an integer target, find three integers in nums such that... ### Convert Roman to Integer number - Leet Code Solution

Problem Statement Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. ### Longest Common Prefix - Leet Code Solution

Problem Statement Write a function to find the longest common prefix string amongst an array of strings. ### Integer to Roman conversion - Leet Code Solution

Problem Statement Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value... ### Container with Most Water - Leet Code Solution

Problem Statement Given n non-negative integers a1, a2, …, an , where each represents a point at coordinate (i, ai).... ### Check whether an integer number given is palindrome or not - Leet Code Solution

Problem Statement Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward... ### Remove nth Node from Last - Leet Code Solution

Problem Statement Given a linked list, remove the n-th node from the end of list and return its head. ### How to prepare for your next Coding Interview

Here are some tips while preparing for your coding interviews. ### How to calculate angle between hour and minute hand, given a time

This problem is a simple mathematical calculation. Lets start deriving some equations. Note: Here we are talking about the round... ### Convert String to Integer - atoi - Leet Code Solution

Problem Statement Implement atoi which converts a string to an integer. ``` Example 1: Input: “42” Output: 42 ### Check whether number is palindrome or not - Leet Code Solution

Problem Statement Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward... ### Zigzag Pattern String Conversion - Leet Code Solution

Problem Statement The string “PAYPALISHIRING” is written in a zigzag pattern on a given number of rows like this: (you... ### Reverse digits of a signed integer - Leet Code Solution

Problem Statement Given a signed integer, reverse digits of an integer. ### Longest Palindrome Substring - Leet Code Solution

Problem Statement Given a string s, find the longest palindromic substring in s. You may assume that the maximum length... ### Find the Median of Two Sorted Arrays - Leet Code Solution

Problem Statement There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of... ### Longest Substring without repeating characters - Leet Code Solution

Problem Statement Given a string, find the length of the longest substring without repeating characters. ### Add two numbers(reverse order) link list Problem - Leet Code Solution

Problem Statement You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order... A number consists of digits. Example: 843. Its a 3-digit number. Radix sort, start by sorting numbers first by their... ### Counting Sort Algorithm

Counting sort runs on relatively smaller set of input. Counting sort calculates, for every element in array - X, the... ### Young Tableau problem - Cormen

Young Tableau A a X b matrix is Young Tableau if all rows(from left to right) and columns(from top to... ### Min Priority Queue Implementation with Heap Data structure

Min Priority Queue is a data structure which manage a list of keys(values). And, gives priority to element with minimum... ### Max Priority Queue Implementation with Heap Data structure

Max Priority Queue is a data structure which manage a list of keys(values). And, gives priority to element with maximum... ### Two Sum Problem - Leet Code Solution

Problem Statement Given an array of integers, return indices of the two numbers such that they add up to a... ### Heap Sort Algorithm

This is another very useful sorting algorithm based on Heap data structure. Read more about Heap Data Structure ### What is Heap Data Structure

Its a tree based data structure which is a complete binary tree(all nodes have 2 nodes, leaf-child may not have... ### Index for Coding Problems

Sorting Problems Merge Sort Quick Sort Heap Sort Bubble Sort Selection Sort Insertion Sort Count Sort Radix Sort ### How to nail your Coding Interview

Here are some tips while giving your coding interviews. ### Maximum Subarray Problem

Problem Statement You are given an array of integers. And, you have find the range of indexes or sub-array from... ### Quick Sort Algorithm

This algorithm is very useful for large input. And, is quite efficient one. It has several implementation, and it is... ### Counting Inversions Coding Problem

** Inversion There is an array(a) and two indexes i and j. Inversion is the element for whom i <... ### Merge Sort Algorithm

This algorithm is very efficient one, and is classic example of Divide and Conquer algorithms. ### Bubble Sort Algorithm

This is kind of preliminary technique of sorting. And, this is the first algorithm that a beginner learns. ### Coding Interview - Useful Terms Cheatsheet

Big-O notation In simpler terms, its kind of a unit to measure how efficient an algorithm is, with respect to... ### Selection Sort Algorithm

It is one of a simple algorithm to study for a beginner to understanding sorting algorithms. ### Insertion Sort Algorithm

Its a kind of incremental insertion technique, where the algorithm build up sorting by first sorting n-1 items. ### List of Sorting Algorithms

This topic is one of the most common studied. When somebody started preparation of coding interviews. Sorting algorithms would in... ### Coding Interview Cheatsheet

Absolute Must Have Below are must have topics that you must know: Algorithms Data Structures Concepts Breadth First Search (BFS)...