Binary tree inorder traversal without recursion using stack

In this blog we are going to discuss how to implement binary tree inorder traversal without recursion using stack.

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#include <iostream>
#include<stack>
using namespace std;

typedef struct l
{
        struct l* left;
        struct l* right;
        int data;
} Tree;

Tree *node(int data)
{
    Tree *tmp = new Tree();
    tmp->left = NULL;
    tmp->right = NULL;
    tmp->data = data;
    return tmp;
}
void inorder(Tree* root)
{

}
void inorderTraversal(Tree* root)
{
    if (root == NULL) return ;

    Tree* current = root;
    stack<Tree*> s;
    int flag = 0;

    while (!flag)
    {
        while (current != NULL) // Inserting all leftmost nodes
        {
            s.push(current);
            current = current->left;
        }

        if (!s.empty())
        {
            current = s.top();
            cout << current->data<<" ";
            s.pop();
            current = current->right;
        }
        else
            flag = 1;
    }
}

int main()
{
    Tree* root = node(6);
    root->left = node(8);
    root->right = node(5);
    root->right->left = node(8);
    root->right->right = node(3);
    inorderTraversal(root);
    return 0;
}

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