DSA/algorithms/CPlusPlus/Trees/binary-search-tree.cpp

241 lines
6.2 KiB
C++

#include <iostream>
#include <cmath>
//Structure of the Tree
struct TreeNode{
int data;
TreeNode* left;
TreeNode* right;
TreeNode(const int& data): data(data), left(nullptr), right(nullptr){}
};
TreeNode* find(TreeNode* root, const int& data){
/**
* Find the node that contains the given data and
* return that node
*
* @params: `root` root/parent node of the tree
* @params: `data` data to be find in the tree
* @return: tree node that contains the data
*
* Average case Time Complexity: O(log(n))
* Worst case Time Complexity: O(n)
*
*/
if(root == nullptr) { throw std::runtime_error("Error: find() cannot find the data. The data doesn't exist."); }
else if(root->data == data) { return root; }
else if(root->data < data) { return find(root->right, data); }
else { return find(root->left, data); }
}
void Insert(TreeNode*& root, const int& data){
/**
* Create and Insert the node in the appropriate place of the tree
*
* @params: `root` root/parent node of the tree
* @params: `data` data to be inserted in the tree
* @return: void
*
* Average case Time Complexity: O(log(n))
* Worst case Time Complexity: O(n)
*
*/
if(root == nullptr) { root = new TreeNode(data); }
else if(root->data == data) { throw std::runtime_error("The node already exist. Duplicates not allowed"); }
else if(root->data < data) { Insert(root->right, data); }
else { Insert(root->left, data); }
}
bool isfull(TreeNode* root){
/**
*
* Check if a binary tree is full or not
* A binary tree is full when every node in the
* tree has either two or zero child nodes.
*
* @params: `root` root/parent node of the tree
*
* @return: true if it the binary tree is full else false
*/
if(root == nullptr) { return true; }
if(root->left == nullptr && root->right == nullptr) { return true; }
if((root->left != nullptr && root->right != nullptr) ) { return isfull(root->left) && isfull(root->right); }
return false;
}
int depth(TreeNode* root){
/**
* Find the depth of the left most tree.
* Here the depth of the left most tree is found but
* it is only a matter of preference.
*
* @params: `root` root/parent node of the tree
*
* @return: `d` returns the depth of the left most tree
*/
int d = 0;
while(root != nullptr){
root = root->left;
d++;
}
return d;
}
bool perfect_recursive(TreeNode* cur, int depth, int level = 0){
/**
* A Recursive strategy to check if a tree is perfect or not
*
* A binary tree is perfect if when all the inner node's
* has two children and the all the leaf node's are at the
* same level.
*
* @params: `cur` node of the tree
* @params: `depth` depth of the left most tree
* @params: `level` level of the cur node
*
* @return: true if the binary tree is perfect else false
*/
if(cur == nullptr) { return true; }
if(cur->left == nullptr && cur->right == nullptr) { return depth == level; }
if(cur->left != nullptr && cur->right != nullptr) {
return perfect_recursive(cur->left, depth, level+1) && perfect_recursive(cur->right, depth, level+1);
}
return false;
}
int count_nodes(TreeNode* cur){
/**
* Count the number of node's in the tree
* @params: `cur` node of the tree
*/
if(cur != nullptr){ return 1 + count_nodes(cur->left) + count_nodes(cur->right); }
return 0;
}
int height(TreeNode* cur){
/**
* Find the height of the tree
*
* @params: `cur` node of the tree
*/
if(cur != nullptr){ return 1 + std::max(height(cur->left), height(cur->right)); }
return 0;
}
bool perfect(TreeNode* cur){
/**
* Knowing the height and the number of node's of
* the tree we can find whether the tree is perfect or not
*
* A binary tree is perfect if when all the inner node's
* has two children and the all the leaf node's are at the
* same level.
*/
int h = height(cur) - 1;
int N = count_nodes(cur);
if(N == pow(2, h+1) - 1) { return true; }
return false;
}
bool isperfect(TreeNode* root){
/**
*
* @params: `root` root/parent node of the tree
*
* @return: true if the binary tree is perfect else false
*/
//if(perfect(root)) { return true; }
if(perfect_recursive(root, depth(root) - 1)) { return true; }
return false;
}
void print(TreeNode* root){
/**
* Print the tree in an inorder fashion
*
* @params: `root` root/parent node of the tree
* @return: void
*/
if(root != nullptr){
print(root->left);
std::cout << root->data << " ";
print(root->right);
}
}
void free(TreeNode* root){
/*
* Free up the memory in the heap
*
* @params: `root` root/parent node of the tree
*/
if(root != nullptr){
free(root->left);
free(root->right);
delete root;
root = nullptr;
}
}
int main(){
TreeNode* root = nullptr;
Insert(root, 37);
Insert(root, 19);
Insert(root, 4);
Insert(root, 22);
Insert(root, 51);
Insert(root, 55);
Insert(root, 42);
Insert(root, 20);
Insert(root, 11);
Insert(root, 2);
print(root);
TreeNode* n = find(root, 19);
std::cout << "\nValue of n: " << n->data << std::endl;
if(isfull(root)) { std::cout << "The binary tree is FULL" << std::endl; }
else { std::cout << "The binary tree is not FULL" << std::endl; }
if(isperfect(root)) { std::cout << "The binary tree is PERFECT" << std::endl; }
else { std::cout << "The binary tree is not PERFECT" << std::endl; }
/*
Tree structure
37
/ \
19 51
/ \ / \
4 22 42 55
/\ /
2 11 20
OUTPUT:
2 4 11 19 20 22 37 42 51 55
Value of n: 19
The binary tree is not FULL
The binary tree is not PERFECT
*/
// free the memory
free(root);
return 0;
}