Geeksforgeeks Graph Theory Code Example

Example: graph c++

//Code by Soumyadeep Ghosh insta- @soumyadepp //linked in :  https://www.linkedin.com/in/soumyadeep-ghosh-90a1951b6/ //Basic implementation of undirected graph using OOP  #include <bits/stdc++.h>  using namespace std;  //undirected graph class graph {   vector<int>*adjacency_list; //array of vectors to store adjacency list   int Vertices;   public:     //constructor     graph(int n)     {       Vertices=n;       adjacency_list=new vector<int>[Vertices]; //dynamic allocation     }        void add_edge(int,int);     void display_graph(); };  int main() {   graph g1(5);  //graph of 5 vertices indices- 0 to 4   //adding edges   g1.add_edge(0,1); //connect node number 0 to node number 1   g1.add_edge(1,2); //connect node number 1 to node number 2   g1.add_edge(1,3); //connect node number 1 to node number 3   g1.add_edge(2,4); //connect node number 2 to node number 4   g1.add_edge(2,3); //connect node number 2 to node number 3   //displaying the graph   cout<<"The entered Graph is "<<endl;   g1.display_graph();   return 0; }  //function definitions void graph::add_edge( int u,int v )    {      if( u >= Vertices || v >= Vertices )      {        cout<<"Overflow"<<endl;        return;      }      if( u<0 || v<0 )      {        cout<<"underflow"<<endl;        return;      }      adjacency_list[u].push_back(v);      adjacency_list[v].push_back(u);    }   void graph::display_graph()    {      for(int i=0;i<Vertices;i++)      {        cout<<"Adjacency list of vertex of vertex "<<i<<endl;        for(auto it:adjacency_list[i]) //traverse through each list        {          cout<<it<<" ";        }        cout<<endl;      }    } //thank you!