Binary Tree Printing

[KappuJ]

Hi,
I need to print a binary tree
1. in the order of its level ( root, left & right child, children of the left & right nodes, its children & so on )
1, 2, 3, 4, 5, 6,7,8 .... where 2 & 3 are the children of 1, 4 & 5 are the children of 2, 6 & 7 are the children of 3 & so on...


2. print them in the following manner
1
2
3

[TheCPUWizard]

Does the tree contain OBJECTS or Integers?

[KappuJ]

The tree contains simple integers

[cup]

You have a strange binary tree. Normally it is left, middle then right but you want it printed as middle, left right. Oh well - we all have our reasons. Assuming the structure is

struct bintree
{
    struct bintree* left;
    struct bintree* right;
    int val;
};

Printing it is just

void printtree (struct bintree* node)
{
     cout << node->val << endl;
    if (node->left != 0) printree (node->left);
    if (node->right != 0) printree (node->right);
}

or if you are likely to start with a null node then
void printtree (struct bintree* node)
{
    if (node != 0)
    {
        cout << node->val << endl;
        printtree (node->left);
        printtree (node->right);
    }
}

The latter looks neater but nests more deeply at runtime. If you wanted it as left, value, right, just move the printree of the left before the cout.

[galathaea]

Are you trying to print them like

1
     2
          4
          5
     3
          6
          7

I was curious since you posted twice, and maybe weren't familiar as to how to get the tabbing to show up...

[Yves M]

Originally posted by galathaea
I was curious since you posted twice

Sorry, no that was me. While writing the post he accidentally posted the half-done post and TheCPUWizard replied to that. I then merged the full question with this thread. But by deleting the first (uncomplete) post, I would delete the whole thread. Ok, I'm not trying to explain my life here, just that it's a technical glitch