#include <iostream>
struct TreeNode {
int val;
TreeNode* left;
TreeNode* right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
void preorderTraversal(TreeNode* root) {
if (root == NULL) {
return;
}
std::cout << root->val << " ";
preorderTraversal(root->left);
preorderTraversal(root->right);
}
int main() {
TreeNode* root = new TreeNode(1);
root->left = new TreeNode(2);
root->right = new TreeNode(3);
root->left->left = new TreeNode(4);
root->left->right = new TreeNode(5);
std::cout << "Preorder Traversal: ";
preorderTraversal(root);
return 0;
}