Adjacency Matrix Graph In C

Adjacency Matrix Graph: In this post we will study about the implementation of adjacency matrix graph.

The given code have 4 major functions:

• One is creating the edge
• One is removing the edge
• One is checking the edge
• Other is printing the edge

Adjacency Matrix Graph Code In C

#include<stdio.h>
#define V 5

void def(int arr[][V])
{
    int i,j;
    for(i = 0; i < V; i++)
        for(j = 0; j < V; j++)
            arr[i][j] = 0;
}

void addEdge(int arr[][V],int a, int b)
{
     arr[a][b] = 1;   
}

void print(int arr[][V])
{
     int i, j;
     for(i = 0; i < V; i++)
     {
         for(j = 0; j < V; j++)
         {
             printf("%d ", arr[i][j]);
         }
         printf("\n");
     }
}

int hasEdge(int arr[][V], int a, int b)
{
    if(arr[a][b] == 1)
        return 1;

    return 0;
}

void removeEdge(int arr[][V], int a, int b)
{
    arr[a][b] = 0;
}

int main()
{
    int adj[V][V];
    def(adj);

    addEdge(adj,0,1);
    addEdge(adj,1,2);
    addEdge(adj,2,1);
    addEdge(adj,3,3);
    addEdge(adj,4,3);

    print(adj);

    printf("Removing Edge(0, 1)\n");
    removeEdge(adj,0,1);

    print(adj);

    printf("(0,1) has Edge?\n");
    if(hasEdge(adj,0, 1) == 1)
        printf("Edge Found\n");
    else
        printf("Edge Not Found\n");

    printf("(0,2) has Edge?\n");

    return 0;   
}

In the above code, we are doing following things:

• First we are creating a matrix and initializing 0 values to each rows and columns.
• After this if we want to add an edge between any two vertices then we will make that equal to 1.
• If we want to remove then we will again update the value to 0.
• So we are using two dimensional array concept to implement adjacency matrix graph.