7.BST traversal methods

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

// Node structure
struct node {
    int data;
    struct node *left, *right;
};

// Create node
struct node* create(int x) {
    struct node* newnode = (struct node*)malloc(sizeof(struct node));
    newnode->data = x;
    newnode->left = newnode->right = NULL;
    return newnode;
}

// Insert
struct node* insert(struct node* root, int x) {
    if (root == NULL)
        return create(x);

    if (x < root->data)
        root->left = insert(root->left, x);
    else
        root->right = insert(root->right, x);

    return root;
}

// Traversals
void inorder(struct node* root) {
    if (root != NULL) {
        inorder(root->left);
        printf("%d ", root->data);
        inorder(root->right);
    }
}

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

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

// Main
int main() {
    struct node* root = NULL;
    int ch, x;

    do {
        printf("\n--- BST MENU ---\n");
        printf("1.Insert\n2.Inorder\n3.Preorder\n4.Postorder\n5.Exit\n");
        printf("Enter choice: ");
        scanf("%d", &ch);

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

            case 2:
                printf("Inorder: ");
                inorder(root);
                printf("\n");
                break;

            case 3:
                printf("Preorder: ");
                preorder(root);
                printf("\n");
                break;

            case 4:
                printf("Postorder: ");
                postorder(root);
                printf("\n");
                break;

            case 5:
                printf("Exiting...\n");
                break;

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

    } while (ch != 5);

    return 0;
}