Thread: fill the gaps question..

i am given two bst trees
fill the gaps so it will return the number nodes which are equal in both trees

Code:

typedef struct Node{
int Val;
struct Node *Left, *Right;
} Node;

int CommonNodes(Node *T1, Node *T2) 
{
    if ( ?? 1 ?? || ?? 2 ?? )
	return 0;
				
    if ( ?? 3 ?? == ?? 4 ?? ) 
	return  ?? 5 ?? + ?? 6 ?? + ?? 7 ?? ;

    if ( ?? 8 ?? ) 
	return  CommonNodes(?? 9 ??) + CommonNodes(?? 10 ??)
   - CommonNodes(?? 11 ??) ;

   if ( ?? 12 ??  ) 
	return  ?? 13 ?? + ?? 14 ?? - ?? 15 ?? ;
}

i tried like this
i know that its some how about
when we take the same common nodes twice
so we ned to subtract that group
but i cant see when it happens

Code:

int CommonNodes(Node *t1, Node *t2) 
{
    if (!t1||!t2 )
	return 0;
				
    if ( t1->val == t2->val) 
	return  CommonNodes(t1->left,t2->left) + CommonNodes(t1->right,t2->right) +1;

    if ( ?? 8 ?? ) 
	return  CommonNodes(?? 9 ??) + CommonNodes(?? 10 ??)
   - CommonNodes(?? 11 ??) ;

   if ( ?? 12 ??  ) 
	return  ?? 13 ?? + ?? 14 ?? - ?? 15 ?? ;
}

nope you havent me how?

no its not working like that.
i told you what the last part is about
but i dont know when it happens

but these have a different algorithm.
i have it on the tip of my tongue.
the answer is
we have two groups
and in those two groups we have a common numbers
so when we what to find the total number of values.
we sum the amount of values in the first group with the amount of values in the second group
and we delete the common numbers.(because we counted them twice)

this is what they want in the last part
but i cant figure out how to do that in that case in practice
??

No effort = No thread.

Closed. And I actually get to close this before Salem.