Teori graf (c++)

#include <iostream>

using namespace std;


/* A binary tree node has data, pointer to left child
and a pointer to right child */

struct Node
{

    int data;

    struct Node* left, *right;

    Node(int data)

    {

        this->data = data;

        left = right = NULL;

    }
};


/* Given a binary tree, print its nodes according to the
"bottom-up" postorder traversal. */

void printPostorder(struct Node* node)
{

    if (node == NULL)

        return;



    // first recur on left subtree

    printPostorder(node->left);



    // then recur on right subtree

    printPostorder(node->right);



    // now deal with the node

    cout << node->data << " ";
}


/* Given a binary tree, print its nodes in inorder*/

void printInorder(struct Node* node)
{

    if (node == NULL)

        return;



    /* first recur on left child */

    printInorder(node->left);



    /* then print the data of node */

    cout << node->data << " ";



    /* now recur on right child */

    printInorder(node->right);
}


/* Given a binary tree, print its nodes in preorder*/

void printPreorder(struct Node* node)
{

    if (node == NULL)

        return;



    /* first print data of node */

    cout << node->data << " ";



    /* then recur on left sutree */

    printPreorder(node->left);



    /* now recur on right subtree */

    printPreorder(node->right);
}


/* Driver program to test above functions*/

int main()
{

    struct Node *root = new Node(1);

    root->left             = new Node(2);

    root->right         = new Node(3);

    root->left->left     = new Node(4);

    root->left->right = new Node(5);



    cout << "\nPreorder traversal of binary tree is \n";

    printPreorder(root);



    cout << "\nInorder traversal of binary tree is \n";

    printInorder(root);



    cout << "\nPostorder traversal of binary tree is \n";

    printPostorder(root);



    return 0;
}