Graph-BFS


Lear Theory - BFS

/** BFS Implementation *************/

#include <stdio.h>
#include <stdlib.h>

#define MAX_VERTICES 10

// Function to perform Breadth-First Search (BFS)
void bfs(int startVertex, int visited[MAX_VERTICES], int adjacencyMatrix[MAX_VERTICES][MAX_VERTICES], int numVertices) {
    // Create a queue for BFS
    int queue[MAX_VERTICES];
    int front = -1, rear = -1;

    // Enqueue the startVertex
    queue[++rear] = startVertex;
    visited[startVertex] = 1;

    while (front != rear) {
        // Dequeue a vertex from the front of the queue
        int currentVertex = queue[++front];
        printf("V%d ", currentVertex ); // Assuming vertex labels are 'V0', 'V1', 'V2', ...

        // Enqueue all unvisited neighbors
        for (int i = 0; i < numVertices; i++) {
            if (adjacencyMatrix[currentVertex][i] == 1 && !visited[i]) {
                queue[++rear] = i;
                visited[i] = 1;
            }
        }
    }
}
int main() {
    int numVertices, i, j;

    printf("Enter the number of vertices (max %d): ", MAX_VERTICES);
    scanf("%d", &numVertices);

    // Input the adjacency matrix
    int adjacencyMatrix[MAX_VERTICES][MAX_VERTICES];
    printf("Enter the adjacency matrix (1 for connected, 0 for not connected):\n");
    for (i = 0; i < numVertices; i++) {
        for (j = 0; j < numVertices; j++) {
            scanf("%d", &adjacencyMatrix[i][j]);
        }
    }

    // Array to keep track of visited vertices
    int visited[MAX_VERTICES] = {0};

    // Perform BFS starting from each unvisited vertex
    printf("BFS Traversal Order:\n");
    for (i = 0; i < numVertices; i++) {
        if (!visited[i]) {
            bfs(i, visited, adjacencyMatrix, numVertices);
        }
    }

    return 0;
}



/****  Alternate Implementation of BFS *********/

#include <stdio.h>
struct vertex{
int num;
int visit;
}Q[50],v[50],t;

int adj[50][50],n,f=-1,r=-1;
void addq(struct vertex v)
{
r++;
Q[r]=v;
}
struct vertex deleteq()
{
++f;
return(Q[f]);
}
int qempty()
{
if(f==r) return 1;else return 0;
}
void bfs()
{ int i;
    addq(v[1]);v[1].visit=1;
    while(!qempty())
    {
    t=deleteq();
    
    printf("V%d-------->",t.num);
   
     for(i=1;i<=n;i++) if(adj[t.num][i]==1 && v[i].visit==0) {addq(v[i]);v[i].visit=1;}
  }
}

void read()
{ int ad,i;
printf("Enter the Number of vertices\n");
scanf("%d",&n);
// storing element from [1][1]
//// assuming the vertices are numbered v1 v2..vn and we will enter only the index 1,2...n
for(i=1;i<=n;i++) {v[i].num=i;v[i].visit=0;}
for(i=1;i<=n;i++)
{
    printf("Enter the list of vertices adjacent to v%d -1 to stop\n",i);
    while(1)
   {
     scanf("%d",&ad);
    if(ad==-1) break;
    adj[i][ad]=1;
    }
}
}//end of read
void disp()
{
printf("Adjacency Matrix..\n");
for(int i=1;i<=n;i++)
{
for(int j=1;j<=n;j++)
    printf("%5d",adj[i][j]);
printf("\n");
}
}
int main()
{
read();
disp();
printf("Breadth First Search Result\n");
bfs();
return 0;
}

Comments

Post a Comment

Popular posts from this blog

Data Structure Lab CSL 201 Manual KTU - Dr Binu V P-9847390760

 Dr Binu V P - About Me Data Structures CST 201 KTU Theory Notes  ( Learn Theory Before You Attempt Lab Exercise) SCHEME AND SYLLABUS 1. Polynomial Addition using Arrays 2. Sparse Matrix Representation and sum 3. Stack using Array 4. Queue using Array 5. Circular Queue using Arrays 6. Double Ended Queue  7. Priority Queue  8. Infix to postfix 9. Infix to prefix conversion 10. Prefix to infix conversion 11. Evaluation of postfix expression 12. Singly Linked List 13. Doubly Linked List   14. Stack using Linked List 15. Queue using Linked List 16. Polynomial Addition using Linked list 17. Polynomial Multiplication using Linked List 18. Binary Tree using arrays and traversals 19. Binary Tree using Linked List and Traversal 20. Binary Search Tree Implementation and Traversal 21.Sorting Algorithms       Bubble sort       Exchange sort       Selection Sort       Insertion Sort       Quick Sort ...
Read more

Singly Linked List Implementation

Singly Linked List /**************************************************************************/ #include<stdio.h> #include<stdlib.h> struct Node {  int data;  struct Node *next; }*head=NULL,*tail=NULL,*temp=NULL,*trav=NULL,*prev=NULL; void create() {  temp=(struct Node*)malloc(sizeof(struct Node));  printf("Enter data:");  scanf("%d",&temp->data);  temp->next=NULL;  if(head==NULL)  {   head=temp;   tail=temp;  }  else  {   tail->next=temp;   tail=temp;  } } void display() {  temp=head;  while(temp!=NULL)  {   printf(" %d---->",temp->data);   temp=temp->next;  }  printf(" NULL"); }  void insert_begin()  {      temp=(struct Node*)malloc(sizeof(struct Node));      printf("Enter data:");      scanf("%d",&temp->data);      temp->next=NULL;      if(head...
Read more

Binary search Tree Implementation and Traversal

Binary Search Tree and Operations /******* BST Tree and Operations **********/ #include <stdio.h> #include <stdlib.h>struct Node { int key; struct Node* left; struct Node* right; }; struct Node *root=NULL,*temp=NULL; struct Node* createNode(int key) {      struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));      newNode->key = key;      newNode->left = newNode->right = NULL;      return newNode; } struct Node* insert(struct Node* node, int key) { // Base case: if the tree is empty, create a new node if (node == NULL) {      return createNode(key);      } // Compare the key with the current node's key if (key < node->key) { // Recursively insert into the left subtree      node->left = insert(node->left, key);      } else if (key > node->key) { // Recursively insert into the right subtree    node->...
Read more