Update datastructs/binarysearchtree example

+ Utilize copy-swap idiom, miscellaneous clean-up of conditions and return values
This commit is contained in:
Shaun Reed 2021-06-09 11:00:02 -04:00
parent a8b6627135
commit 8f211b1603
4 changed files with 177 additions and 173 deletions

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@ -8,9 +8,14 @@
#
cmake_minimum_required(VERSION 3.15)
# Define the project name
project(BinarySearchTree)
# Define source files
set(SRC driver.cpp bst.cpp)
# Build an executable
add_executable(BSTDriver ${SRC})
project (
#[[NAME]] BinaryTree
VERSION 1.0
DESCRIPTION "A project for testing a basic implementation of a BST"
LANGUAGES CXX
)
add_library(lib-bst "bst.cpp")
add_executable(test-bst "driver.cpp")
target_link_libraries(test-bst lib-bst)

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@ -1,10 +1,10 @@
/*#############################################################################
/*##############################################################################
## Author: Shaun Reed ##
## Legal: All Content (c) 2020 Shaun Reed, all rights reserved ##
## Legal: All Content (c) 2021 Shaun Reed, all rights reserved ##
## About: An example of a binary search tree implementation ##
## ##
## Contact: shaunrd0@gmail.com | URL: www.shaunreed.com | GitHub: shaunrd0 ##
##############################################################################
################################################################################
## bst.cpp
*/
@ -21,27 +21,17 @@
* @param rhs The BST to copy, beginning from its root BinaryNode
* @return const BinarySearchTree& The copied BinarySearchTree object
*/
const BinarySearchTree& BinarySearchTree::operator=(const BinarySearchTree& rhs)
BinarySearchTree& BinarySearchTree::operator=(BinarySearchTree rhs)
{
// If the objects are already equal, do nothing
if (this == &rhs) return *this;
// Empty this->root
makeEmpty();
// Copy rhs to this->root
root = clone(rhs.root);
std::swap(root, rhs.root);
return *this;
}
/** Default Destructor
* @brief Destroy the Binary Search Tree:: Binary Search Tree object
*/
BinarySearchTree::~BinarySearchTree()
{
makeEmpty(root);
}
/********************************************************************************
* Public Member Functions
*********************************************************************************/
@ -52,9 +42,9 @@ BinarySearchTree::~BinarySearchTree()
*
* @return const int& The element of the BinaryNode that holds the lowest value in our tree
*/
const int & BinarySearchTree::findMin() const
int BinarySearchTree::findMin() const
{
return findMin(root)->element;
return findMin(root) != nullptr ? findMin(root)->element: INT32_MIN;
}
/** findMax
@ -63,9 +53,9 @@ const int & BinarySearchTree::findMin() const
*
* @return const int& The element of the BinaryNode that holds the highest value in our tree
*/
const int & BinarySearchTree::findMax() const
int BinarySearchTree::findMax() const
{
return findMax(root)->element;
return findMax(root) != nullptr ? findMax(root)->element: INT32_MIN;
}
/** contains
@ -84,12 +74,12 @@ bool BinarySearchTree::contains(const int &x) const
/** isEmpty
* @brief Determine whether or not the calling BST object is empty
*
* @return true If this->root node points to an empty tree (NULL)
* @return true If this->root node points to an empty tree (nullptr)
* @return false If this->root node points to a constructed BinaryNode
*/
bool BinarySearchTree::isEmpty() const
{
return root == NULL;
return root == nullptr;
}
/** insert
@ -167,7 +157,7 @@ void BinarySearchTree::printPreOrder() const
BinarySearchTree::BinaryNode * BinarySearchTree::clone(BinaryNode *t) const
{
// If there is nothing to copy
if (t == NULL) return NULL;
if (t == nullptr) return nullptr;
// Construct all child nodes through recursion, return root node
return new BinaryNode(t->element, clone(t->left), clone(t->right));
@ -181,14 +171,10 @@ BinarySearchTree::BinaryNode * BinarySearchTree::clone(BinaryNode *t) const
*/
void BinarySearchTree::insert(const int &x, BinarySearchTree::BinaryNode *&t) const
{
if (t == NULL)
t = new BinaryNode(x, NULL, NULL);
else if (x < t->element)
insert (x, t->left);
else if (x > t->element)
insert (x, t->right);
else
return;
if (t == nullptr) t = new BinaryNode(x, nullptr, nullptr);
else if (x < t->element) insert (x, t->left);
else if (x > t->element) insert (x, t->right);
else return;
}
/** remove
@ -199,14 +185,11 @@ void BinarySearchTree::insert(const int &x, BinarySearchTree::BinaryNode *&t) co
*/
void BinarySearchTree::remove(const int &x, BinarySearchTree::BinaryNode *&t) const
{
if (t == NULL)
return;
if (t == nullptr) return;
if (x < t->element)
remove(x, t->left);
else if (x > t->element)
remove(x, t->right);
else if (t->left != NULL && t->right != NULL) {
if (x < t->element) remove(x, t->left);
else if (x > t->element) remove(x, t->right);
else if (t->left != nullptr && t->right != nullptr) {
// If we found the node and there are two branches
t->element = findMin(t->right)->element;
std::cout << "Removing [" << t->element << "]...\n";
@ -215,7 +198,7 @@ void BinarySearchTree::remove(const int &x, BinarySearchTree::BinaryNode *&t) co
else {
// If we found the value and there is only one branch
BinaryNode *oldNode = t;
t = (t->left != NULL) ? t->left : t->right;
t = (t->left != nullptr) ? t->left : t->right;
std::cout << "Removing [" << oldNode->element << "]...\n";
delete oldNode;
}
@ -225,40 +208,32 @@ void BinarySearchTree::remove(const int &x, BinarySearchTree::BinaryNode *&t) co
* @brief Find the minimum value within the BST of the given BinaryNode
*
* @param t The root BinaryNode to begin checking values
* @return BinarySearchTree::BinaryNode* The BinaryNode which contains the smallest value (returns NULL if BST is empty)
* @return BinarySearchTree::BinaryNode* The BinaryNode which contains the smallest value (returns nullptr if BST is empty)
*/
BinarySearchTree::BinaryNode * BinarySearchTree::findMin(BinarySearchTree::BinaryNode *t) const
{
while (t != NULL)
t = t->left;
// If our tree is empty
if (t == NULL)
return NULL;
if (t == nullptr) return nullptr;
while (t->left != nullptr) t = t->left;
// If current node has no smaller children, it is min
if (t->left == NULL)
return t;
// Move down the left side of our tree and check again
return findMin(t->left);
}
/** findMax
* @brief Find the maximum value within the BST of the given BinaryNode
*
* @param t The root BinaryNode to begin checking values
* @return BinarySearchTree::BinaryNode* The BinaryNode which contains the largest value (returns NULL if BST is empty)
* @return BinarySearchTree::BinaryNode* The BinaryNode which contains the largest value (returns nullptr if BST is empty)
*/
BinarySearchTree::BinaryNode * BinarySearchTree::findMax(BinarySearchTree::BinaryNode *t) const
{
// If our tree is empty
if (t == NULL)
return NULL;
if (t == nullptr) return nullptr;
// If current node has no larger children, it is max
if (t->right == NULL)
return t;
if (t->right == nullptr) return t;
// Move down the right side of our tree and check again
return findMax(t->right);
@ -274,14 +249,13 @@ BinarySearchTree::BinaryNode * BinarySearchTree::findMax(BinarySearchTree::Binar
*/
bool BinarySearchTree::contains(const int &x, BinarySearchTree::BinaryNode *t) const
{
if (t == NULL) // If tree is empty
return false;
else if (x < t->element) // If x is smaller than our current value
return contains(x, t->left);// Check left node
else if (x > t->element) // If x is larger than our current value
return contains(x, t->right); // Check right node
else
return true;
// If tree is empty
if (t == nullptr) return false;
// If x is smaller than our current value
else if (x < t->element) return contains(x, t->left);
// If x is larger than our current value, check the right node
else if (x > t->element) return contains(x, t->right);
else return true;
}
/** makeEmpty
@ -291,12 +265,12 @@ bool BinarySearchTree::contains(const int &x, BinarySearchTree::BinaryNode *t) c
*/
void BinarySearchTree::makeEmpty(BinarySearchTree::BinaryNode * & t)
{
if (t != NULL) {
if (t != nullptr) {
makeEmpty(t->left);
makeEmpty(t->right);
delete t;
}
t = NULL;
t = nullptr;
}
/** printInOrder
@ -306,7 +280,7 @@ void BinarySearchTree::makeEmpty(BinarySearchTree::BinaryNode * & t)
*/
void BinarySearchTree::printInOrder(BinaryNode *t) const
{
if(t != NULL) {
if(t != nullptr) {
printInOrder(t->left);
std::cout << t->element << " ";
printInOrder(t->right);
@ -320,7 +294,7 @@ void BinarySearchTree::printInOrder(BinaryNode *t) const
*/
void BinarySearchTree::printPostOrder(BinaryNode *t) const
{
if (t != NULL) {
if (t != nullptr) {
printPostOrder(t->left);
printPostOrder(t->right);
std::cout << t->element << " ";
@ -328,13 +302,13 @@ void BinarySearchTree::printPostOrder(BinaryNode *t) const
}
/** printPreOrder
* @brief Output the value of the noot nodes before their subtrees
* @brief Output the value of the root nodes before their subtrees
*
* @param t The root BinaryNode to begin the 'Pre Order' output
*/
void BinarySearchTree::printPreOrder(BinaryNode *t) const
{
if (t != NULL) {
if (t != nullptr) {
std::cout << t->element << " ";
printPreOrder(t->left);
printPreOrder(t->right);

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@ -1,10 +1,10 @@
/*#############################################################################
/*##############################################################################
## Author: Shaun Reed ##
## Legal: All Content (c) 2020 Shaun Reed, all rights reserved ##
## Legal: All Content (c) 2021 Shaun Reed, all rights reserved ##
## About: An example of a binary search tree implementation ##
## ##
## Contact: shaunrd0@gmail.com | URL: www.shaunreed.com | GitHub: shaunrd0 ##
##############################################################################
################################################################################
## bst.h
*/
@ -16,13 +16,13 @@
// TODO: Add balance() method to balance overweight branches
class BinarySearchTree {
public:
BinarySearchTree() : root(NULL) {};
BinarySearchTree(const BinarySearchTree &rhs) : root(rhs.clone(rhs.root)) {};
const BinarySearchTree& operator=(const BinarySearchTree& rhs);
~BinarySearchTree();
const int & findMin() const;
const int & findMax() const;
public:
BinarySearchTree() : root(nullptr) {};
BinarySearchTree(const BinarySearchTree &rhs) : root(clone(rhs.root)) {};
BinarySearchTree& operator=(BinarySearchTree rhs);
~BinarySearchTree() { makeEmpty(root);};
int findMin() const;
int findMax() const;
bool contains(const int &x) const;
bool isEmpty() const;
void insert(const int &x);
@ -32,7 +32,7 @@ class BinarySearchTree {
void printPostOrder() const;
void printPreOrder() const;
private:
private:
struct BinaryNode{
int element;
BinaryNode *left;
@ -41,6 +41,7 @@ class BinarySearchTree {
:element(el), left(lt), right(rt) {};
};
BinaryNode *root;
BinaryNode * clone(BinaryNode *t) const;
void insert(const int &x, BinaryNode *&t) const;
void remove(const int &x, BinaryNode *&t) const;

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@ -1,24 +1,26 @@
/*#############################################################################
/*##############################################################################
## Author: Shaun Reed ##
## Legal: All Content (c) 2020 Shaun Reed, all rights reserved ##
## Legal: All Content (c) 2021 Shaun Reed, all rights reserved ##
## About: A driver program to test a binary search tree implementation ##
## ##
## Contact: shaunrd0@gmail.com | URL: www.shaunreed.com | GitHub: shaunrd0 ##
##############################################################################
################################################################################
## driver.cpp
*/
#include "bst.h"
#include <iostream>
enum OPS {
EXIT, INSERT, REMOVE, CONTAINS, INFIX, PREFIX, POSTFIX, EMPTY, MIN, MAX
EXIT, INSERT, REMOVE, CONTAINS, INFIX, PREFIX, POSTFIX, EMPTY, MIN, MAX,
COPY, EQUAL
};
int main()
{
std::cout << "Driver: \n";
BinarySearchTree testList;
BinarySearchTree testTree;
bool exit = false;
int choice = -1;
int val;
@ -26,8 +28,9 @@ int main()
while (!exit)
{
std::cout << "##### Binary Search Tree Menu #####\n\t0. Exit"
"\n\t1. Insert\n\t2. Remove\n\t3. Contains\n\t4. Infix\n\t5. Prefix"
<< "\n\t6. Postfix\n\t7. Empty\n\t8. Min\n\t9. Max\n";
"\n\t1. Insert\n\t2. Remove\n\t3. Contains\n\t4. In-order\n\t"
"5. Pre-order\n\t6. Post-order\n\t7. Empty\n\t8. Min\n\t9. Max"
"\n\t10. Copy BST\n\t11. Equal BST\n";
std::cin >> choice;
std::cin.clear();
switch (choice) {
@ -39,49 +42,70 @@ int main()
std::cout << "Enter a value to insert to our tree: ";
std::cin >> val;
std::cin.clear();
testList.insert(val);
testTree.insert(val);
break;
case REMOVE:
std::cout << "Enter a value to remove from our tree: ";
std::cin >> val;
std::cin.clear();
testList.remove(val);
testTree.remove(val);
break;
case CONTAINS:
std::cout << "Enter a value to search for within our tree: ";
std::cin >> val;
std::cin.clear();
if (testList.contains(val))
std::cout << val << " exists within our tree\n";
else std::cout << val << " does not exist within our tree\n";
if (testTree.contains(val)) std::cout << val << " exists in our tree\n";
else std::cout << val << " does not exist in our tree\n";
break;
case INFIX:
testList.printInOrder();
testTree.printInOrder();
break;
case PREFIX:
testList.printPreOrder();
testTree.printPreOrder();
break;
case POSTFIX:
testList.printPostOrder();
testTree.printPostOrder();
break;
case EMPTY:
testList.makeEmpty();
testTree.makeEmpty();
std::cout << "The BST is empty: "
<< (testTree.isEmpty() ? "true" : "false") << std::endl;
break;
case MIN:
std::cout << "Min value within our tree: " << testList.findMin();
std::cout << "Min value within our tree: " << testTree.findMin() << "\n";
break;
case MAX:
std::cout << "Max value within our tree: " << testList.findMax();
std::cout << "Max value within our tree: " << testTree.findMax() << "\n";
break;
case COPY:
{
BinarySearchTree copiedTree(testTree);
std::cout << "Inorder output from copied tree: ";
copiedTree.printInOrder();
std::cout << std::endl;
// copiedTree calls destructor when leaving this scope
break;
}
case EQUAL: {
BinarySearchTree equalTree;
equalTree = testTree;
std::cout << "Inorder output from equal tree: ";
equalTree.printInOrder();
std::cout << std::endl;
// equalTree calls destructor when leaving this scope
break;
}
default:
std::cout << "Invalid entry...\n";
break;