Difference traversal methods

traverse.cpp

#include <iostream>

class Node
{
public:
    Node(int data, Node* left = nullptr, Node* right = nullptr)
        : data(data)
        , left(left)
        , right(right)
    { }
    
    Node& setLeft(int n)  { left  = new Node(n); return *left;  }
    Node& setRight(int n) { right = new Node(n); return *right; }
    
    int data{0};
    Node* left;
    Node* right;
};

void preorder(Node* node)
{
    if (node)
    {
        std::cout << node->data << " ";

        preorder(node->left);
        preorder(node->right);
    }
}

void inorder(Node* node)
{
    if (node)
    {
        inorder(node->left);
            
        std::cout << node->data << " ";

        inorder(node->right);
    }
}

void postorder(Node* node)
{
    if (node)
    {
        postorder(node->left);
        postorder(node->right);
            
        std::cout << node->data << " ";
    }
}

int main()
{
    Node root(50);
    
    auto& l  = root.setLeft(25);
    auto& r  = root.setRight(75);
    
    l.setLeft(1);
    l.setRight(12);
    r.setLeft(62);
    r.setRight(100);
    
    std::cout << std::boolalpha;
    
    std::cout << "Preorder: ";
    preorder(&root);
    
    std::cout << "\nInorder: ";
    inorder(&root);
    
    std::cout << "\nPostorder: ";
    postorder(&root);
}

Preorder: 50 25 1 12 75 62 100
Inorder: 1 25 12 50 62 75 100
Postorder: 1 12 25 62 100 75 50