BST.CPP

#include <stdio.h>
#include <conio.h>
#include <malloc.h>
struct tree
{
    int data;
    struct tree *left, *right;
};
typedef struct tree node;
node *root;
void insert(void);
void search(void);
void inorder(node *ptr);
void preorder(node *ptr);
void postorder(node *ptr);
int main()
{
    int c;
    clrscr();
    do
    {
        printf("\n press 1 for insert");
        printf("\n press 2 for search");
        printf("\n press 3 for inorder ");
        printf("\n press 4 for preorder ");
        printf("\n press 5 for postorder ");
        printf("\n press 0 for exit");
        scanf("%d", &c);
        if (c == 1)
        {
            insert();
        }
        else if (c == 2)
        {
            search();
        }
        else if (c == 3)
        {
            inorder(root);
        }
        else if (c == 4)
        {
            preorder(root);
        }
        else if (c == 5)
        {
            postorder(root);
        }
    } while (c != 0);
    getch();
    return 0;
}
void insert(void)
{
    int f = 0;
    node *temp, *ptr, *parent;
    temp = (node *)malloc(sizeof(node));
    printf("\n enter any number");
    scanf("%d", &temp->data);
    temp->left = NULL;
    temp->right = NULL;
    if (root == NULL)
    {
        root = temp;
    }
    else
    {
        ptr = root;
        while (ptr->data != temp->data)
        {
            parent = ptr;
            if (temp->data < ptr->data)
            {
                ptr = ptr->left;
                if (ptr == NULL)
                {
                    f = 1;
                    break;
                }
            }
            else if (temp->data > ptr->data)
            {
                ptr = ptr->right;
                if (ptr == NULL)
                {
                    f = 2;
                    break;
                }
            }
            else if (ptr->data == temp->data)
            {
                printf("\n node already exist");
            }
        }
    }

    if (f == 1)
    {
        parent->left = temp;
    }
    else if (f == 2)
    {
        parent->right = temp;
    }
}

void search()
{
    node *ptr;
    int c;
    printf("\n enter tthe number for search");
    scanf("%d", &c);

    ptr = root;
    while (ptr->data != c)
    {
        printf("\n %d", ptr->data);
        if (c < ptr->data)
        {
            ptr = ptr->left;
            if (ptr == NULL)
            {
                printf("\nnodenot found in the list");
                break;
            }
        }
        else if (c > ptr->data)
        {
            ptr = ptr->right;
            if (ptr == NULL)
            {
                printf("\n nodeis not found in the list");
                break;
            }
        }
        else if (c == ptr->data)
        {
            printf("\n no. isfound in the list");
        }
    }
}

void inorder(node *ptr)
{
    if (ptr != NULL)
    {
        inorder(ptr->left);
        printf("\t %d", ptr->data);
        inorder(ptr->right);
    }
}

void preorder(node *ptr)
{
    if (ptr != NULL)
    {
        printf("\t %d", ptr->data);
        preorder(ptr->left);
        preorder(ptr->right);
    }
}

void postorder(node *ptr)
{
    if (ptr != NULL)
    {
        postorder(ptr->left);
        postorder(ptr->right);
        printf("\t %d", ptr->data);
    }
}