Binary Tree with Pre/Post/Inorder Traversal in C++

#include <iostream>
#include <string>
#include <stdio.h>
#include <stdlib.h>
using namespace std;

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

/* allocates a new node with the NULL left and right pointers. */
struct node* newNode(int data)
{
struct node* node = (struct node*)
malloc(sizeof(struct node));
node->data = data;
node->left = NULL;
node->right = NULL;

return(node);
}

/* Given the tree, print nodes, 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
printf(“%d “, node->data);
}

/* print 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 */
printf(“%d “, node->data);
/* now recur on right child */
printInorder(node->right);
}

/* print nodes in preorder*/
void printPreorder(struct node* node)
{
if (node == NULL)
return;
/* first print data of node */
printf(“%d “, node->data);
/* then recur on left sutree */
printPreorder(node->left);
/* now recur on right subtree */
printPreorder(node->right);
}

int main()
{
struct node *root = newNode(1);
root->left = newNode(2);
root->right = newNode(3);
root->left->left = newNode(4);
root->left->right = newNode(5);

printf(“\n Preorder traversal of binary tree is \n”);
printPreorder(root);
printf(“\n Inorder traversal of binary tree is \n”);
printInorder(root);
printf(“\n Postorder traversal of binary tree is \n”);
printPostorder(root);

getchar();
return 0;
system(“pause”);
return 0;
}

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