Mr. Duck's BST - Easy BST

#include <bits/stdc++.h>
using namespace std;

const int N = 1010;
int pre[N];

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

node *insert(node *root, int data) {

    if (!root) {
        node *newNode = new node;
        newNode->data = data;
        newNode->left = newNode->right = NULL;
        return newNode;
    }
    if (data < root->data)
        root->left = insert(root->left, data);
    else
        root->right = insert(root->right, data);
    return root;
}

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

int main()
{
    int n;
    scanf("%d", &n);
    node *root = NULL;
    for (int i = 0; i < n; ++i) {
        int x;
        scanf("%d", &x);
        root = insert(root, x);
    }

    postorder(root);

    return 0;
}