How can I represent graphs in C++?

How can I represent graphs in C++?

You can represent graphs in C++ using adjacency lists or adjacency matrices. Which one would you like to know more about?

What's the difference between adjacency lists and matrices?

Adjacency lists use less space for sparse graphs and are more efficient for traversals, while matrices are easier for dense graphs but use more memory.

Can you show me an example of an adjacency list implementation?

Sure! Here's a simple implementation using a vector of lists in C++:

#include <iostream>
#include <vector>
#include <list>

class Graph {
    int V; // Number of vertices
    std::vector<std::list<int>> adj;
public:
    Graph(int V);
    void addEdge(int v, int w);
    void printGraph();
};

Graph::Graph(int V) {
    this->V = V;
    adj.resize(V);
}

void Graph::addEdge(int v, int w) {
    adj[v].push_back(w);
}

void Graph::printGraph() {
    for (int v = 0; v < V; v++) {
        std::cout << "Vertex " << v << " : ";
        for (int w : adj[v]) {
            std::cout << w << " ";
        }
        std::cout << std::endl;
    }
}

This creates a graph and allows you to add edges.

What about using a class for the graph?

Using a class is a great idea! It encapsulates the graph's properties and methods, making your code cleaner and more modular.