Question

In C++ I need the printRange function, and the main.cpp program. Thanks.

(Binary search tree) Write a function printRange that takes as input a binary search tree t and two keys, k1 and k2, which are ordered so that k1 < k2, and print all elements x in the tree such that k1 <= x <= k2.

You can add this function in BinarySearchTree.h (click the link) that we used in the lecture and lab 7.

public:

void printRange(int k1, int k2)

{ printRange(root,k1, k2);

}

private:

void printRange(BinaryNode* t, int k1, int k2)

{

// add your code

}

Here are the sample runs:

insert the values (stop when entering 0): 10 5 20 3 22 6 18 7 9 13 15 4 2 1 19 30 8 0

enter the range of values: 8 18

print the values: 8, 9, 10, 13, 15, 18,

Here is BinarySearchTree.h

#ifndef BINARY_SEARCH_TREE_H
#define BINARY_SEARCH_TREE_H

#include <cassert>
#include <iostream>
using namespace std;      

template <typename C>
class BinarySearchTree
{
  public:
    BinarySearchTree( ) : root{ nullptr }
    {
    }

    ~BinarySearchTree( ) 
    { 
        makeEmpty();
    }   

    bool isEmpty( ) const
    {
        return root == nullptr;
    } 

    const C & findMin( ) const
    {
      assert(!isEmpty());
      return findMin( root )->element;
    }

    const C & findMax( ) const
    {
      assert(!isEmpty());
      return findMax( root )->element;
    }
    
    bool contains( const C & x ) const
    {
        return contains( x, root );
    }  

    void printTree( ) const
    {
        if( isEmpty( ) )
            cout << "Empty tree" << endl;
        else
            printTree( root );
    }

    void makeEmpty( )
    {
        makeEmpty( root );
    }
    
    void insert( const C & x )
    {
        insert( x, root );
    }     

    void remove( const C & x )
    {
        remove( x, root );
    }

  private:
    
    struct BinaryNode
    {
        C element;
        BinaryNode* left;
        BinaryNode* right;

        BinaryNode( const C & theElement, BinaryNode* lt, BinaryNode* rt )
          : element{ theElement }, left{ lt }, right{ rt } 
        { }
    };

    BinaryNode* root;
    
    // Internal method to find the smallest item in a subtree t.
    // Return node containing the smallest item.    
    BinaryNode* findMin( BinaryNode* t ) const
    {
        if( t == nullptr )
            return nullptr;
        if( t->left == nullptr )
            return t;
        return findMin( t->left );
    }
    
    // Internal method to find the largest item in a subtree t.
    // Return node containing the largest item.
    BinaryNode* findMax( BinaryNode* t ) const
    {
        if( t != nullptr )
            while( t->right != nullptr )
                t = t->right;
        return t;
    }

    // Internal method to test if an item is in a subtree.
    // x is item to search for.
    // t is the node that roots the subtree.    
    bool contains( const C & x, BinaryNode* t ) const
    {
        if( t == nullptr )
            return false;
        else if( x < t->element )
            return contains( x, t->left );
        else if( t->element < x )
            return contains( x, t->right );
        else
            return true;    // Match
    }

    void printTree( BinaryNode* t) const
    {
        if( t != nullptr )
        {
            printTree( t->left);
            cout << t->element << " - ";
            printTree( t->right);
        }
    }
    
    void makeEmpty( BinaryNode* & t )
    {
        if( t != nullptr )
        {
            makeEmpty( t->left );
            makeEmpty( t->right );
            delete t;
        }
        t = nullptr;
    }
    
    // Internal method to insert into a subtree.
    // x is the item to insert.
    // t is the node that roots the subtree.
    // Set the new root of the subtree.    
    void insert( const C & x, BinaryNode* & t )
    {
        if( t == nullptr )
            t = new BinaryNode{ x, nullptr, nullptr };
        else if( x < t->element )
            insert( x, t->left );
        else if( t->element < x )
            insert( x, t->right );
        else
            ;  // Duplicate; do nothing
    }
    
    // Internal method to remove from a subtree.
    // x is the item to remove.
    // t is the node that roots the subtree.
    // Set the new root of the subtree.    
    void remove( const C & x, BinaryNode* & t )
    {
        if( t == nullptr )
            return;   // Item not found; do nothing
        if( x < t->element )
            remove( x, t->left );
        else if( t->element < x )
            remove( x, t->right );
        else if( t->left != nullptr && t->right != nullptr ) // Two children
        {
            t->element = findMin( t->right )->element;
            remove( t->element, t->right );
        }
        else
        {
            BinaryNode* oldNode = t;
            if ( t->left == nullptr )
                t = t->right;
            else
                t = t->left;
            delete oldNode;
        }
    }

};
#endif

Answer 1

//C ++ program

public:

void printRange(int k1, int k2)

{ printRange(root,k1, k2);

}

private:

void printRange(BinaryNode* root, int k1, int k2)

{
   /* base case */
if ( root == NULL )
return;
  
/* Since the desired o/p is sorted, recurse for left subtree first
If root->data is greater than k1, then only we can get o/p keys
in left subtree */
if ( k1 < root->data )
printRange(root->left, k1, k2);
  
/* if root's data lies in range, then prints root's data */
if ( k1 <= root->data && k2 >= root->data )
cout<< root->data ;
  
/* If root->data is smaller than k2, then only we can get o/p keys
in right subtree */
if ( k2 > root->data )
printRange(root->right, k1, k2);

}