C Program for Breadth First Search #214

Search/breathfirstsearch

@@ -0,0 +1,35 @@
+#include<stdio.h>
+#include<conio.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;
+	clrscr();
+	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");
+	getch();
+}