BFS Algorithm C Code with Queue implementation. You have to have "matris.txt" file for nodes. Don't miss it.

bfs.c

#include <stdio.h>
#include <stdbool.h>

int graph[6][6];
bool visited[5];

struct node{
    int data;
    struct node *next;
};

struct node* first = NULL;
struct node* last = NULL;

struct node* createNode(int x)
{
    struct node* newNode = (struct node*)malloc(sizeof(struct node));
    newNode->data = x;
    newNode->next = NULL;
    return newNode;
}

void enQueue(int x)
{
    struct node* newyNode = createNode(x);
    if(first == NULL)
    {
        first = newyNode;
        last = newyNode;
    }
    else
    {
        last->next = newyNode;
        last = newyNode;
    }
}

void deQueue()
{
    if(first == NULL)
    {
        printf("\n Your Queue is already empty please enqueue an item");
        return;
    }

    if(first->next == NULL)
    {
        first = NULL;
        last = NULL;
    }
    else
    {
        struct node* secondNode = first->next;
        free(first);
        first = secondNode;
    }

}

bool isEmpty()
{
    if(first == NULL)
        return true;
    else
        return false;
}

int next()
{
    return first->data;
}

void BFS(int root)
{
    int i;
    for(i = 0; i < 6; i++)
    {
        visited[i] = false;
    }

    visited[root]  = true;
    enQueue(root);

    while(isEmpty() == false)
    {
        root = next();
        printf("%d ", root);
        deQueue();

        for( i = 0; i < 6; i++)
        {
            if(visited[i] == false && graph[root][i] == 1)
            {
                visited[i] = true;
                enQueue(i);
            }
        }
    }
}

void readGraph()
{
    int i = 0;
    FILE *fp = fopen("matris.txt", "r");
    while(fscanf(fp, "%d %d %d %d %d %d",
                 &graph[i][0],
                 &graph[i][1],
                 &graph[i][2],
                 &graph[i][3],
                 &graph[i][4],
                 &graph[i][5]) !=EOF){
        i = i + 1;
    }

}

int main()
{
    readGraph();
    BFS(2);
    return 0;
}

matris.txt

0 1 1 0 0 0
1 0 0 1 0 0
1 0 0 1 0 0
0 1 1 0 1 0
0 0 0 1 0 1
0 0 0 0 1 0