Thread: determine if tree is strictly binary bst

Hi, need a little help on this one.
I need to write a member function to determine if my BST is
strictly binary or not. The function should do this through a
series of if statements, and simply printing out a message.
The complication is, it needs recursive calls, and I'm not too good
with those.
I've written the function, and it works, but it's printing a tree ahead of
time, so there are several printouts when there supposed to be only one.

Here is the function:



void BST::strict() //this function is public to be called by main()
{
strict(theroot);
}
//


//private functon, gets a pointer to tree node.
//called by public strict().
//Will determine if a tree is strictly binary
//or not, and then rint a message.
void BST::strict(Tnode *p)
{

bool ans;
ans =false;

if(p == NULL)

ans = true;
else if((p->right == NULL && p->left == NULL) || (p->right != NULL && p->left != NULL)){
strict(p->left);
strict(p->right);

ans =true;
}
else if((p->right == NULL && p->left != NULL) || (p->right != NULL && p- >left == NULL)){
ans =false;
}

//else
// //cout<<"The tree is NOT strictly binary!!!"<<endl;
// ans =2;


if(ans ==true){
cout<<"The tree is strictly binary!!!"<<endl;
}
else if(ans ==false){
cout<<"The tree is NOT strictly binary!!!"<<endl;
}


}





here is the output:



Here is the 1st Tree traversal:
INORDER:
-3 1 10 54 97

PREORDER:
10 -3 1 97 54

POSTORDER:
1 -3 54 97 10

Smalest item in the tree: -3
Largest item in the tree: 97
Largest item in left subtree: 1
Smallest item in right subtree: 54

The tree is NOT strictly binary!!!
The tree is NOT strictly binary!!!
The tree is strictly binary!!!




Here is the 2nd Tree traversal:
INORDER:
7 10 20

PREORDER:
10 7 20

POSTORDER:
7 20 10

Smalest item in the tree: 7
Largest item in the tree: 20
Largest item in left subtree: 7
Smallest item in right subtree: 20

The tree is strictly binary!!!
The tree is strictly binary!!!
The tree is strictly binary!!!
The tree is strictly binary!!!
The tree is strictly binary!!!
The tree is strictly binary!!!
The tree is strictly binary!!!




Here is the 3rd Tree traversal:
INORDER:
0 1 15 19 20 20 30 81

PREORDER:
0 20 15 1 19 30 20 81

POSTORDER:
1 19 15 20 81 30 20 0

Smalest item in the tree: 0
Largest item in the tree: 81
Largest item in left subtree: 0
Smallest item in right subtree: 1

The tree is NOT strictly binary!!!




Here is the 4th Tree traversal:
INORDER:
1 3 4 5 6 8 10 11 13 15

PREORDER:
10 5 4 1 3 6 8 15 11 13

POSTORDER:
3 1 4 8 6 5 13 11 15 10

Smalest item in the tree: 1
Largest item in the tree: 15
Largest item in left subtree: 8
Smallest item in right subtree: 11

The tree is NOT strictly binary!!!
The tree is NOT strictly binary!!!
The tree is strictly binary!!!
The tree is NOT strictly binary!!!
The tree is strictly binary!!!




Here is the 5th Tree traversal:
INORDER:


PREORDER:


POSTORDER:


Smalest item in the tree:
Largest item in the tree:
Largest item in left subtree:
Smallest item in right subtree:

The tree is strictly binary!!!


Press any key to continue . . .

This is a standalone function.... can easily be converted to member function

Code:

bool IsStrictlyBinary(Node* root) {

	if(root->left == NULL && root->right == NULL)
		return true;
	else if ((root->left == NULL && root->right != NULL)  ||
		(root->right == NULL && root->left != NULL)	)
		return false;	
	else
		return ((IsStrictlyBinary(root->left))?IsStrictlyBinary(root->right):false);
}