The ultimate guide to coding interviews. Developed by FAANG engineers. Boost problem-solving skills with number theory, dynamic programming, and graph theory. Get interview-ready in just a few hours.

Competitive Programming - Crack Your Coding Interview.png

Whether you’re gearing up for online coding challenges, code-a-thons, or interviews, then this course is for you. With this course, you will solidify your problem-solving skills ensuring a swift sail through any problem. 


You will be tasked with solving some of the most frequently asked questions that are brought up in FAANG interviews. You will start with the concepts of Number Theory and Divide and Conquer, and gradually move towards more complex problems like dynamic programming and graph theory.


With each problem you solve, there will be insightful explanations and full implementation details to really hammer home the concepts. By the time you finish this course, you will have the confidence to solve any problem, no matter the difficulty.

Competitive Programming - Crack Your Coding Interview, C++

# Introduction
*Backtracking* is a general algorithmic technique that considers searching every possible combination order to solve an optimization problem. Backtracking is also known as a depth-first search or branch and bound. The Recursion technique is always used to solve backtracking problems. Let's start first with Recursion.

# Recursion

When a function calls itself, it is called Recursion. We can use the example of the movie **Inception** (dir. Christopher Nolan, 2010) to understand this. The lead in the film, played by Leonardo DiCaprio had a dream, and in that dream, he had another dream, in which he had yet another dream, and so on. Recursion is just like that: there is a function called `dream()` and we are just calling it in itself.
```
function dream()
{
   print "Dreaming":
   dream();
}
```
Recursion is useful in solving problems that can be broken down into smaller problems of the same kind. There are several things to be taken care of when using Recursion.

 Let's take a simple example and try to understand it. The following is the pseudocode of finding the factorial of a given number `X` using Recursion:
```
function factorial(x)
{
   if (x == 0) // base case
      return 1;
   else
      return x*factorial(x - 1); // break into smaller problems
}
```
The following slides show how it works for `factorial(5)`:

Learn the logic building for Recursion and Backtracking.

Overview

Number Theory

Number Theory

Divide and Conquer

Greedy Algorithms

Greedy Algorithms

Recursion and Backtracking

Recursion and Backtracking

Dynamic Programming

Graphs

Bonus Lessons

Introduction to Recursion & Backtracking

Introduction

Recursion