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++

# Implementation
This implementation requires basic knowledge of **vectors**. Let us jump right into the code. 

#include<iostream>
#include<list>
using namespace std;
class Graph
{
    int V;
    list<int> *l;
    public:
    Graph(int v)
    {
        V = v;
        l = new list<int>[V]; //Array of Linked Lists
    }
    void addEdge(int u,int v,bool bidir=true)
    {
        l[u].push_back(v);
        if(bidir)
            l[v].push_back(u);
    }
    void printAdjList()
    {
        for(int i=0;i<V;i++)
        {
            cout<<i<<"->";
            for(int vertex: l[i])
                cout<<vertex<<",";
            cout<<endl;
        }
    }
};

int main(){
    // Graph has 5 vertices number from 0 to 4
    Graph g(5);
    g.addEdge(0,1);
    g.addEdge(0,4);
    g.addEdge(4,3);
    g.addEdge(1,4);
    g.addEdge(1,2);
    g.addEdge(2,3);
    g.addEdge(1,3);
    g.printAdjList();
    return 0;
}

**Explanation:**
* On line 4, we define our class `Graph` to create a graph structure.
* On line 6, we define an integer variable that will store the value of a node. *Here, we have taken only the integer data.*
* On line 7, we define a linked list header pointer only.
* On line 9,  we define our constructor to create our graph. Here we also instantiate the list that we created in the above step.
* On line 14, we define the function `addEdge()` that will add an edge between the two nodes `u` and `v`. Also, we can pass a boolean value that can determine whether the graph is undirected (bi-directional) or directed.
* On line 16, we push `v` node in the `u` node's list. 
* On line 18, if the edge is bi-directional, then we also push `u` node in the `v` node's list.
* On line 20, we create a function `printAdjList()` to print our graph. We will print the graph as an adjacency list representation.
* On line 25, we used a `for-each` loop to print the elements in each list.
* On line 34, we initialize the graph with `5` nodes.
* Then, we create the edges between the nodes.
* Finally, on line 42, we print the adjacency list representation of the graph.

Learn to implement the adjacency list representation of a graph.

Overview

Number Theory

Number Theory

Divide and Conquer

Greedy Algorithms

Greedy Algorithms

Recursion and Backtracking

Recursion and Backtracking

Dynamic Programming

Graphs

Bonus Lessons

Adjacency List Representation - Implementation

Implementation