Question

#include <iostream>

#include <cstddef>

using std::cout;

using std::endl;

class Node {

    int value;

public:

    Node* left;       // left child

    Node* right;      // right child

    Node* p;          // parent

    Node(int data) {

        value = data;

        left = NULL;

        right = NULL;

        p  = NULL;

    }

    ~Node() {

    }

    int d() {

        return value;

    }

    void print() {

        std::cout << value << std::endl;

    }

};

int main(int argc, const char * argv[])

{

}

function insert(Node *insert_node, Node *tree_root){

        //Your code here

}

function delete_node(int value, Node *tree_root){

        //Your code here

}

function search(int value, Node *tree_root){

        //Your code here

}

1. Implement insert() in tree.cpp and show the results of inserting 2, 1, 4, 5, 9, 3, 6, 7, 10, 12, 11 into an empty Binary search tree.
2. Start with the tree in problem 1 and implement delete_node() and do:
   1. delete 4, then
   2. delete 9.
3. Start with the tree in problem 2 and implement search() and do:
   1. Search 12

Answer 1

//C ++ program

#include<iostream>
using namespace std;

class Node {
int value;
public:
Node* left; // left child
Node* right; // right child
Node* p; // parent
Node(int data) {
value = data;
left = NULL;
right = NULL;
p = NULL;
}
~Node() {
}
int d() {
return value;
}
void print() {
std::cout << value << std::endl;
}
void setValue(int v){
   value = v;
   }
};

Node* insert(Node *insert_node, Node *tree_root){
if (tree_root == NULL) return insert_node;

if (insert_node->d() < tree_root->d())
tree_root->left = insert(insert_node,tree_root->left);
else if (insert_node->d() > tree_root->d())
tree_root->right = insert(insert_node,tree_root->right);   

return tree_root;
}

Node*findmin(Node*tree_root){
   while(tree_root&&tree_root->left){
       tree_root=tree_root->left;
   }
   return tree_root;
}

Node* delete_node(int value, Node *tree_root){
Node*temp;
   if(!tree_root)return NULL;
   else if(tree_root->d()<value)tree_root->right=delete_node(value,tree_root->right);
   else if(tree_root->d()>value)tree_root->left=delete_node(value,tree_root->left);
   else if(tree_root->d()==value){
       if(!tree_root->left){
           temp=tree_root->right;
           delete(tree_root);
           return temp;
       }
       if(!tree_root->right){
           temp=tree_root->left;
           delete(tree_root);
           return temp;
       }
       temp=findmin(tree_root->right);
       tree_root->setValue(temp->d());
       tree_root->right=delete_node(temp->d(),tree_root->right);
   }
   else
       cout<<"key not found\n";
  
  
   return tree_root;
}

Node* search(int value, Node *tree_root){
if (tree_root == NULL || tree_root->d() == value)
return tree_root;

// Key is greater than root's key
if (tree_root->d() < value)
return search(value,tree_root->right);
  
// Key is smaller than root's key
return search(value,tree_root->left);
}

void inorder(Node*tree_root){
   if(tree_root==NULL)return;
   inorder(tree_root->left);
   tree_root->print();
   inorder(tree_root->right);
}

int main(int argc, const char * argv[])
{
int arr[] = {2, 1, 4, 5, 9, 3, 6, 7, 10, 12, 11};
int n = sizeof(arr)/sizeof(arr[0]);
Node*tree = NULL;
  
for(int i=0;i<n;i++){
   tree = insert(new Node(arr[i]),tree);
   }
   cout<<"Inorder Traversal :\n";
   inorder(tree);
   tree = delete_node(4,tree);
   cout<<"\nInorder Traversal after deleting 4:\n";
   inorder(tree);
  
   tree = delete_node(9,tree);
   cout<<"\nInorder Traversal after deleting 9:\n";
   inorder(tree);
  
   if(search(12,tree))cout<<"\n12 found in tree\n";
   else cout<<"\n12 not found in tree\n";
  
   return 0;
}
//sample output