BST Tree

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

struct Node {
    int data;
    struct Node *left;
    struct Node *right;
};

struct Node* createNode(int value) {
    struct Node *newNode = malloc(sizeof(struct Node));

    if (newNode == NULL) {
        printf("Memory allocation failed!\n");
        exit(1);
    }

    newNode->data = value;
    newNode->left = NULL;
    newNode->right = NULL;

    return newNode;
}

struct Node* insert(struct Node *root, int value) {
    if (root == NULL)
        return createNode(value);

    if (value < root->data)
        root->left = insert(root->left, value);
    else if (value > root->data)
        root->right = insert(root->right, value);
    else
        printf("Duplicate value ignored!\n");

    return root;
}

int search(struct Node *root, int value) {
    if (root == NULL)
        return 0;

    if (root->data == value)
        return 1;

    if (value < root->data)
        return search(root->left, value);

    return search(root->right, value);
}

void inorder(struct Node *root) {
    if (root == NULL)
        return;

    inorder(root->left);
    printf("%d ", root->data);
    inorder(root->right);
}

void preorder(struct Node *root) {
    if (root == NULL)
        return;

    printf("%d ", root->data);
    preorder(root->left);
    preorder(root->right);
}

void postorder(struct Node *root) {
    if (root == NULL)
        return;

    postorder(root->left);
    postorder(root->right);
    printf("%d ", root->data);
}

int main() {
    struct Node *root = NULL;
    int choice, value;

    do {
        printf("\n\n1. Insert");
        printf("\n2. Search");
        printf("\n3. Inorder");
        printf("\n4. Preorder");
        printf("\n5. Postorder");
        printf("\n6. Exit");
        printf("\nEnter choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter value: ");
                scanf("%d", &value);
                root = insert(root, value);
                break;

            case 2:
                printf("Enter value to search: ");
                scanf("%d", &value);

                if (search(root, value))
                    printf("Element found.\n");
                else
                    printf("Element not found.\n");
                break;

            case 3:
                printf("Inorder: ");
                inorder(root);
                printf("\n");
                break;

            case 4:
                printf("Preorder: ");
                preorder(root);
                printf("\n");
                break;

            case 5:
                printf("Postorder: ");
                postorder(root);
                printf("\n");
                break;

            case 6:
                printf("Exiting...\n");
                break;

            default:
                printf("Invalid choice!\n");
        }

    } while (choice != 6);

    return 0;
}