Program 19 - BFS

	#include <stdio.h>
	#define MAX 100
	int n, a[20][20], visited[20];
	char name[20];
	int Q[MAX], f = -1, r = -1;
	void enqueue(int num) {
	if(r == MAX -1) {
	printf("Queue Overflow\n");
	} else {
	r++;
	Q[r] = num;
	if(f == -1) {
	f = 0;
	}
	}
	}
	int dequeue() {
	int num;
	if(isEmpty()) {
	return -1;
	} else {
	num = Q[f];
	f++;
	return num;
	}
	}
	int isEmpty() {
	if(f == -1 || f > r) {
	return 1;
	} else {
	return 0;
	}
	}
	void BFS(int v) {
	int i;
	visited[v] = 1;
	enqueue(v);
	while(!isEmpty()) {
	v = dequeue();
	printf("%c -> ", name[v]);
	for(i = 0; i < n; i++) {
	if(a[v][i] == 1 && visited[i] == 0) {
	enqueue(i);
	visited[i] = 1;
	}
	}
	}
	}
	int main() {
	int i, j;
	printf("Depth First Search 1.0:\n");
	printf("Enter number of vertices: ");
	scanf("%d", &n);
	printf("Enter name of vertices: ");
	for(i = 0; i < n; i++) {
	// Note the space here
	scanf(" %c", &name[i]);
	}
	for(i = 0; i < n; i++) {
	visited[i] = 0;
	}
	printf("Enter adjacency matrix: \n");
	for(i = 0; i < n; i++) {
	for(j = 0; j < n; j++) {
	scanf("%d", &a[i][j]);
	}
	}
	for(i = 0; i < n; i++) {
	if(visited[i] == 0) {
	BFS(i);
	}
	}
	}