Added BFS C program

bfs.c

@@ -0,0 +1,44 @@
+#include<stdio.h>
+int a[20][20], q[20], visited[20], n, i, j, f = 0, r = -1;
+
+void bfs(int v) {
+	for(i = 1; i <= n; i++)
+		if(a[v][i] && !visited[i])
+			q[++r] = i;
+	if(f <= r) {
+		visited[q[f]] = 1;
+		bfs(q[f++]);
+	}
+}
+
+void main() {
+	int v;
+	printf("\n Enter the number of vertices:");
+	scanf("%d", &n);
+
+	for(i=1; i <= n; i++) {
+		q[i] = 0;
+		visited[i] = 0;
+	}
+
+	printf("\n Enter graph data in matrix form:\n");
+	for(i=1; i<=n; i++) {
+		for(j=1;j<=n;j++) {
+			scanf("%d", &a[i][j]);
+		}
+	}
+
+	printf("\n Enter the starting vertex:");
+	scanf("%d", &v);
+	bfs(v);
+	printf("\n The node which are reachable are:\n");
+
+	for(i=1; i <= n; i++) {
+		if(visited[i])
+			printf("%d\t", i);
+		else {
+			printf("\n Bfs is not possible. Not all nodes are reachable");
+			break;
+		}
+	}
+}