How can I represent graphs in C programming?

How can I represent graphs in C programming?

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

What's the difference between adjacency matrices and adjacency lists?

An adjacency matrix uses a 2D array to represent edges, while an adjacency list uses an array of lists. The matrix is easier for dense graphs, while the list is more space-efficient for sparse graphs.

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

Sure! Here's a simple implementation:

#include <stdio.h>
#include <stdlib.h>

struct Node {
    int vertex;
    struct Node* next;
};

struct Graph {
    int numVertices;
    struct Node** adjLists;
};

struct Graph* createGraph(int vertices) {
    struct Graph* graph = malloc(sizeof(struct Graph));
    graph->numVertices = vertices;
    graph->adjLists = malloc(vertices * sizeof(struct Node*));
    for (int i = 0; i < vertices; i++)
        graph->adjLists[i] = NULL;
    return graph;
}

Would you like to see more details or additional functions?

Yes, please show me how to add edges to the graph.

To add edges, you can create a function like this:

void addEdge(struct Graph* graph, int src, int dest) {
    struct Node* newNode = malloc(sizeof(struct Node));
    newNode->vertex = dest;
    newNode->next = graph->adjLists[src];
    graph->adjLists[src] = newNode;
}

This function adds an edge from src to dest. Would you like to know how to display the graph?