Inorder traversal without recursion.

Solution #1: We can use a stack to implement Inorder traversal without recursion. Here is the code,

void recInorder(struct node* root, stack& s)
{
    struct node* current = root;

    while(1)
    {
        if(current != NULL)
        {
            s.push(current);
            current = current->left;
        }
        else
        {
            if(!s.empty())
            {
                struct node* temp = s.top();
                s.pop();

                printf("%d ", temp->data);

                current = temp->right;
            }
            else
                break;
        }
    }

    printf("\n");
}