Thread: Move binary tree elements to stack

Several things:

• Define "move binary tree elements to stack". There is more than one way to do it.
• You don't provide us with crucial information like how TreePtr and Stack are declared or what G is.
• Use descriptive variable names, not bizarro one-letter crap like D and G. Better yet, get rid of them. You don't need either of them as far as I can tell.
• Don't use globals. Read this: Global Variables Are Bad.
• Don't cast malloc. Read this: FAQ > Casting malloc - Cprogramming.com
• If start and end are local variables, how do you plan to get them out of the function? You need to return them somehow.

"G" is "end" forgot to change when translated code.

It's hard to tell without seeing implementation details, but can you traverse your entire tree and print all node values or destroying the tree freeing all nodes? Can you build a stack by pushing values to it? If you know how to do these in isolation you can easily replace print with push as you traverse the tree.

I can print tree values and delete them. Also i can insert elements into stack but when i do like this it still does not work.

Code:

void move(TreePtr current)
{
     Stack start;
     Stack end;
     int D;
     if (current !=NULL)
     {
        move(current->left);
        intoStack(start, current->element);

        move(current->right);
     }  
}

Like I said earlier:

Originally Posted by anduril462

• If start and end are local variables, how do you plan to get them out of the function? You need to return them somehow.

As you have it, each call creates a separate start and end that exist only in that function, and disappear as soon as the function returns. Not only that, since they contain the result of a malloc, which you never free, you have a memory leak. You need to declare start and end outside your move function, and pass them in.

Now I understood. But how to pass them in?