Perform an iterative BFS traversal over a graph represented using an adjacency matrix.

#include<stdio.h>
#include<stdlib.h>
#define N 20

typedef struct {
	int V;
	int E;
	int **Adj; // since we need 2 dimensional matrix
} Graph;

typedef int element;

typedef struct 
{
	element data[N]; /* queue content */
	int front, length;
} queue;


queue CreateQueue()
{
	queue q;
	q.front = 0; q.length=0;
	return q;
}
int isEmptyQueue(queue q)
{
	return q.length == 0;
}

int isFullQueue(queue q)
{
	return q.length ==N;
}

int EnQueue(queue *q, element e)
{
	if (isFullQueue(*q)) return 0;
	q->data[(q->front + q->length)%N] = e;
	q->length = q->length + 1;
	return 1;
}

int DeQueue(queue *q)
{
	if (isEmptyQueue(*q)) return 0;
	q->front=(q->front + 1) % N;
	q->length--;
	return 1;
}

int Front(queue q, element *e)
{
	if (isEmptyQueue(q)) return 0;
	*e = q.data[q.front];
	return 1;
}


Graph* adjacencyMatrix() {
	int i, u, v;
	Graph* G=(Graph*) malloc(sizeof(Graph));
	printf("Enter the number of Vertices: ");
	scanf("%d", &G->V);
	printf("Enter the number of Edges: ");
	scanf("%d", &G->E);
	G->Adj = (int **)malloc(G->V * sizeof(int*));
	for (u = 0; u < G->V; u++)
		G->Adj[u] = (int *)malloc(G->V * sizeof(int));

	for (u = 0; u<G->V; u++)
		for (v = 0; v<G->V; v++)
			G->Adj[u][v] = 0;
	for (i = 0; i < G->E; i++) {
		printf("Enter the edge: ");
		scanf("%d %d", &u,&v);
		// for undirected graph, set both
		G->Adj[u][v] = 1;
		G->Adj[v][u] = 1;
	}
	return G;
}

void BFSTraversal(Graph* G, int u, int Visited[]) {
	int v, w;
	queue q;
	q = CreateQueue();
	EnQueue(&q, u);
	Visited[u] = 1;
	
	while (Front(q, &v)) {
		DeQueue(&q);
		printf("%d ", v);
		for (w = 0; w < G->V; w++)
			if (!Visited[w] && G->Adj[v][w])
			{
			    Visited[w] = 1; 
				EnQueue(&q, w);
			}
	}

}

void BFS(Graph *G) {
	int i;
    int *Visited;

	Visited = (int *)malloc(G->V * sizeof(int));
	
	for (i = 0; i < G->V; i++)
		Visited[i] = 0;

	// this loop is required if the graph has more than one component
	for (i = 0; i < G->V; i++)
		if (!Visited[i])
			BFSTraversal(G, i, Visited);
}


void test() {
	int u, v;
	Graph *G = adjacencyMatrix();
	BFS(G);
}

int main()
{
	test();
	return 0;
}