A class implementation of Binary Search Tree in C++

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235

/****************************************************************************************** ******************************************************************************************* Chapter 4 Trees and Graphs This is a class implementation of Binary Search Tree (BST), containing: inser(): insert a value in a BST isBalanced(): check if a BST is balanced, a BST is balanced if the difference of left and right subtrees height is atmost one! getHeight(): returns the height of a BST deleteBST(): deletes a BST inOrder(): prints a BST i in-order fashion preOrder(): prints a BST i pre-order fashion postOrder(): prints a BST i post-order fashion By: Hamed Kiani (Sep. 18, 2015) ****************************************************************************************** ******************************************************************************************/ #include "stdafx.h" #include <iostream> using namespace std; // tree node, including left and right pointers, data struct Node{ Node(int value): data(value), left(NULL), right(NULL) {} int data; Node *left; Node *right; }; ///////////////////////////////////////////////////////////////////////////////////////// // BST class class BST{ private: Node *_root; void insert(Node *treeNode, int data); bool isBalanced(Node *treeNode); int getHeight(Node *treeNode); void deleteBST(Node *treeNode); void inOrder(Node * treeNode); void preOrder(Node * treeNode); void postOrder(Node * treeNode); public: BST(); // constructor ~BST(); // destractor void insert(int data){ insert(_root, data);} int getHeight(){return getHeight(_root);} Node * getMaxNode(); Node * getMinNode(); void deleteBST() {deleteBST(_root);} bool isBalanced(){return isBalanced(_root); } void inOrder() {inOrder(_root);} void preOrder(){preOrder(_root);} void postOrder(){postOrder(_root);} }; ///////////////////////////////////////////////////////////////////////////////////////// BST::BST() { _root = NULL; } ///////////////////////////////////////////////////////////////////////////////////////// void BST::insert(Node *treeNode, int data) { if (!treeNode) { treeNode = new Node(data); _root = treeNode; } else { if (data < treeNode->data) { if (!treeNode->left) { Node *treeTemp = new Node(data); treeNode->left = treeTemp; } else insert(treeNode->left, data); } else { if (!treeNode->right) { Node *treeTemp = new Node(data); treeNode->right = treeTemp; } else insert(treeNode->right, data); } } } ///////////////////////////////////////////////////////////////////////////////////////// int BST::getHeight(Node *treeNode) { if (!treeNode) return 0; return 1 + max(getHeight(treeNode->left) , getHeight(treeNode->right)); } ///////////////////////////////////////////////////////////////////////////////////////// bool BST::isBalanced(Node *treeNode) { if (!treeNode) return false; int leftHeight = getHeight(treeNode->left); int rightHeight = getHeight(treeNode->right); if (abs(leftHeight - rightHeight) > 1) return false; return true; } ///////////////////////////////////////////////////////////////////////////////////////// Node * BST::getMaxNode() { if (!_root) { cout << " the BST is empty!" << endl; return NULL; } Node * treeNode = _root; while(treeNode->right) treeNode = treeNode ->right; return treeNode; } ///////////////////////////////////////////////////////////////////////////////////////// Node * BST::getMinNode() { if (!_root) { cout << " the BST is empty!" << endl; return NULL; } Node * treeNode = _root; while(treeNode->left) treeNode = treeNode ->left; return treeNode; } ///////////////////////////////////////////////////////////////////////////////////////// void BST::deleteBST(Node *treeNode) { if (!treeNode) return; Node * curTreeNode = treeNode; Node * leftTreeNode = treeNode->left; Node * rightTreeNode = treeNode->right; delete(curTreeNode); deleteBST(leftTreeNode); deleteBST(rightTreeNode); } ///////////////////////////////////////////////////////////////////////////////////////// BST::~BST() { deleteBST(); } ///////////////////////////////////////////////////////////////////////////////////////// void BST::inOrder(Node * treeNode) { if (!treeNode) return; inOrder(treeNode->left); cout << treeNode->data << " " ; inOrder(treeNode->right); } ///////////////////////////////////////////////////////////////////////////////////////// void BST::preOrder(Node * treeNode) { if (!treeNode) return; cout << treeNode->data << " "; preOrder(treeNode->left); preOrder(treeNode->right); } ///////////////////////////////////////////////////////////////////////////////////////// void BST::postOrder(Node * treeNode) { if (!treeNode) return; postOrder(treeNode->left); postOrder(treeNode->right); cout << treeNode->data << " "; } ///////////////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////////////////////////////////////////////////// int _tmain(int argc, _TCHAR* argv[]) { BST myBST; myBST.insert(5); myBST.insert(10); myBST.insert(3); myBST.insert(51); myBST.insert(110); myBST.insert(13); int h = myBST.getHeight(); cout << "the height of this BSt is : " << h << endl; Node * mx = myBST.getMaxNode(); cout << "max value: " << mx->data << endl; Node * mi = myBST.getMinNode(); cout << "min value: " << mi->data << endl; bool isbal = myBST.isBalanced(); if (isbal) cout << "BST is balanced! " << endl; else cout << "BST is not balanced! " << endl; cout << " in-order traverse is : " << endl; myBST.inOrder();cout << endl; cout << " pre-order traverse is : " << endl; myBST.preOrder();cout << endl; cout << " post-order traverse is : " << endl; myBST.postOrder();cout << endl; }