Depth First Binary of a c pgm

Depth First Binary Tree Search without using Recursion

#include 

#include 

#include 

struct node

{

    int a;

    struct node *left;

    struct node *right;

    int visited;

};

void generate(struct node **, int);

void DFS(struct node *);

void delete(struct node **);

int main()

{

    struct node *head = NULL;

    int choice = 0, num, flag = 0, key;

    do

    {

        printf("\nEnter your choice:\n1. Insert\n2. Perform DFS Traversal\n3. Exit\nChoice: ");

        scanf("%d", &choice);

        switch(choice)

        {

        case 1: 

            printf("Enter element to insert: ");

            scanf("%d", &num);

            generate(&head, num);

            break;

        case 2: 

            DFS(head);

            break;

        case 3: 

            delete(&head);

            printf("Memory Cleared\nProgram terminated\n");

            break;

        default: 

            printf("Not a valid input, try again\n");

        }

    } while (choice != 3);

    return 0;

}

void generate(struct node **head, int num)

{

    struct node *temp = *head, *prev = *head;

    if (*head == NULL)

    {

        *head = (struct node *)malloc(sizeof(struct node));

        (*head)->a = num;

        (*head)->visited = 0;

        (*head)->left = (*head)->right = NULL;

    }

    else

    {

        while (temp != NULL)

        {

            if (num > temp->a)

            {

                prev = temp;

                temp = temp->right;

            }

            else

            {

                prev = temp;

                temp = temp->left;

            }

        }

        temp = (struct node *)malloc(sizeof(struct node));

        temp->a = num;

        temp->visited = 0;

        if (temp->a >= prev->a)

        {

            prev->right = temp;

        }

        else

        {

            prev->left = temp;

        }

    }

}

void DFS(struct node *head)

{

    struct node *temp = head, *prev;

    printf("On DFS traversal we get:\n");

    while (temp && !temp->visited)

    {

        if (temp->left && !temp->left->visited)

        {

            temp = temp->left;

        }

        else if (temp->right && !temp->right->visited)

        {

            temp = temp->right;

        }

        else

        {

            printf("%d  ", temp->a);

            temp->visited = 1;

            temp = head;

        }

    }

}

void delete(struct node **head)

{

    if (*head != NULL)

    {

        if ((*head)->left)

        {

            delete(&(*head)->left);

        }

        if ((*head)->right)

        {

            delete(&(*head)->right);

        }

        free(*head);

    }

}

Output

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 5

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 3

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 2

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 4

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 1

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 7

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 6

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 1

Enter element to insert: 8

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 2

On DFS traversal we get:

1  2  4  3  6  8  7  5  

Enter your choice:

1. Insert

2. Perform DFS Traversal

3. Exit

Choice: 3

Memory Cleared

Program terminated