11. Develop a Program in C for the following operations on Graph(G) of Cities.
a) Create a Graph of N cities using Adjacency Matrix.
b) Print all the nodes reachable from a given starting node in a digraph using DFS/BFS method.
PROGRAM:
#include<stdio.h>
#include<stdlib.h>
int a[50][50], n, visited[50];
int q[20], front = -1, rear = -1;
int s[20], top = -1, count = 0;
void bfs(int v)
{
int i, cur;
visited[v] = 1;
q[++rear] = v;
while (front != rear)
{
cur = q[++front];
for (i = 1; i <= n; i++)
{
if ((a[cur][i] == 1) && (visited[i] == 0))
{
q[++rear] = i;
visited[i] = 1;
printf("%d ", i);
}
}
}
}
void dfs(int v)
{
int i;
visited[v] = 1;
s[++top] = v;
for (i = 1; i <= n; i++)
{
if (a[v][i] == 1 && visited[i] == 0)
{
printf("%d ", i);
dfs(i);
}
}
}
int main()
{
int ch, start, i, j;
printf("\nEnter the number of vertices in graph:");
scanf("%d", & n);
printf("\nEnter the adjacency matrix:\n");
for (i = 1; i <= n; i++)
{
for (j = 1; j <= n; j++)
scanf("%d", & a[i][j]);
}
for (i = 1; i <= n; i++)
visited[i] = 0;
printf("\nEnter the starting vertex: ");
scanf("%d", & start);
printf("\n==>1. BFS: Print all nodes reachable from a given starting node");
printf("\n==>2. DFS: Print all nodes reachable from a given starting node");
printf("\n==>3:Exit");
printf("\nEnter your choice: ");
scanf("%d", & ch);
switch (ch)
{
case 1:
printf("\nNodes reachable from starting vertex %d are: ", start);
bfs(start);
for (i = 1; i <= n; i++)
{
if (visited[i] == 0)
printf("\nThe vertex that is not reachable is %d", i);
}
break;
case 2:
printf("\nNodes reachable from starting vertex %d are:\n", start);
dfs(start);
break;
case 3:
exit(0);
default:
printf("\nPlease enter valid choice:");
}
}OUTPUT:
*************************case-1*************************
Enter the number of vertices in graph:4
Enter the adjacency matrix:
0 1 0 1
0 0 1 0
0 0 0 1
0 0 0 0
Enter the starting vertex: 1
==>1. BFS: Print all nodes reachable from a given starting node
==>2. DFS: Print all nodes reachable from a given starting node
==>3:Exit
Enter your choice: 1
Nodes reachable from starting vertex 1 are: 2 4 3
*************************case-2*************************
Enter the number of vertices in graph:4
Enter the adjacency matrix:
0 1 0 1
0 0 1 0
0 0 0 1
0 0 0 0
Enter the starting vertex: 2
==>1. BFS: Print all nodes reachable from a given starting node
==>2. DFS: Print all nodes reachable from a given starting node
==>3:Exit
Enter your choice: 1
Nodes reachable from starting vertex 2 are: 3 4
The vertex that is not reachable is 1
*************************case-3*************************
Enter the number of vertices in graph:4
Enter the adjacency matrix:
0 1 0 1
0 0 1 0
0 0 0 1
0 0 0 0
Enter the starting vertex: 1
==>1. BFS: Print all nodes reachable from a given starting node
==>2. DFS: Print all nodes reachable from a given starting node
==>3:Exit
Enter your choice: 2
Nodes reachable from starting vertex 1 are: 2 3 4
*************************case-4*************************
Enter the number of vertices in graph:4
Enter the adjacency matrix:
0 1 0 1
0 0 1 0
0 0 0 1
0 0 0 0
Enter the starting vertex: 2
==>1. BFS: Print all nodes reachable from a given starting node
==>2. DFS: Print all nodes reachable from a given starting node
==>3:Exit
Enter your choice: 2
Nodes reachable from starting vertex 2 are: 3 4