Thread: Given two binary search trees, write a function which.....

Originally Posted by letthem

-I create a function which put in an array the elements of a Binary Search Tree (I called it "visitcopy");
-I create two arrays, A1 and A2, for the values of my T1 and T2;
-I create a doublepointer and a pointer to a structured data "struct btree" (this is my new Tree);
-With a for cycle, I make a comparison between the two arrays and everytime I find a common element, I add a node in my new Binary Search Tree.

Don't do that. Binary search trees can be traversed and searched. Traverse over one binary search tree and search the other for its elements, inserting into a third binary search tree each element's value for which there is a match.

If you really want to go with two arrays, then you might as well assume that the binary search trees have degraded into linked lists, so you sort each array then do a single pass to extract the common values. However, you need to take care when constructing the new binary search tree that you don't create one that degrades into a linked list.

Originally Posted by letthem

I know how to search a value in a binary search tree.

Write a function to do this. The function will return true if the value is found, otherwise it will return false.

You can then write another function to visit one of the binary trees and call that function.

Originally Posted by laserlight

Write a function to do this. The function will return true if the value is found, otherwise it will return false.

You can then write another function to visit one of the binary trees and call that function.

Hello Laserlight!

Here there is the function which search a specific value in a Binary Search Tree:

Code:

Booleansearch(structbtree* ptr, floattarget) {   
  if(ptr != NULL) { //It's not a leave        
      if(ptr->value== target) { //FOUND           
          returnTRUE;}      
      else{ // NONtrovato       
           if(target < ptr->value)// vaia sx      
                returnsearch(ptr->left_ptr,target);         
           else// oppurevaia dx             
                returnsearch(ptr->right_ptr,target);      
      }   
 }   
 else 
      return FALSE;}

Let me see if I understood what you said.
You're suggesting to:
1)visit the first binary search tree;
2)use the search function in the second binary search tree for every value of the first binary search tree ;
3) if the search function give as result TRUE, create a new node in the third tree.

Am I correct?

Yes.