Traverse a binary tree

#include <iostream>

using namespace std;

typedef struct bin_tree{

int data;

struct bin_tree *left;

struct bin_tree *right;

} Node;

Node* create_node(int data)

{

Node *n = new Node;

if(n != NULL){

n->data = data;

n->left = NULL;

n->right = NULL;

}

return n;

}

void add_node(Node *r, Node *n, bool is_left)

{

if(is_left){

r->left = n;

}

else{

r->right = n;

}

}

void del_tree(Node *r)

{

if( r == NULL){

return;

}

del_tree(r->left);

del_tree(r->right);

if(r->left == NULL && r->right == NULL){

delete r;

r = NULL;

return;

}

}

void preorder_traverse(Node *r)

{

if(r == NULL){

return;

}

cout << r->data << ", ";

preorder_traverse(r->left);

preorder_traverse(r->right);

}

int main(int argc, char* argv[])

{

Node *root = create_node(100);

Node *n = create_node(50);

add_node(root, n, 1);

Node *n1 = create_node(25);

add_node(n, n1, 1);

n1 = create_node(75);

add_node(n, n1, 0);

n = create_node(150);

add_node(root, n, 0);

n1 = create_node(175);

add_node(n, n1, 0);

n1 = create_node(125);

add_node(n, n1, 1);

n = create_node(110);

add_node(n1, n, 1);

preorder_traverse(root);

del_tree(root);

return 0;

}

Output

100, 50, 25, 75, 150, 125, 110, 175,