Implement insert and delete of Tri-nay tree

Problem

Implement insert and delete In a tri-nary tree. A tri-nary tree is much like a binary tree but with three child nodes for each parent instead of two -- with the left node being values less than the parent, the right node values greater than the parent, and the middle nodes values equal to the parent.

For example, suppose I added the following nodes to the tree in this order: 5, 4, 9, 5, 7, 2, 2. The resulting tree wocould look like this:

  1 /*   2  * Author: Min Li  3  * This code can implement insert and delete in a tri-nary tree.  4  */  5   6 #include<iostream>  7   8 using namespace std;  9  10  11 // Definition for Tree Node 12 struct TreeNode { 13 public: 14         int val; 15         TreeNode *left; 16         TreeNode *right; 17         TreeNode *middle; 18         TreeNode(int x) : val(x), left(NULL), right(NULL), middle(NULL) {} 19 }; 20  21  22 // Class: trinaryTree 23 class trinaryTree { 24 public: 25     TreeNode* insert(TreeNode *root, int value);        // Insert a node 26     TreeNode* deleteNode(TreeNode *root, int value);    // Delete a node 27     TreeNode* findSuccessor(TreeNode *root);            // Find a node‘s successor 28     bool test();                                        // Test my code 29 }; 30  31  32 // Method: Insert a node into tri-nary tree 33 // return the root of new tri-nary tree 34 TreeNode* trinaryTree:: insert(TreeNode *root, int value) { 35     TreeNode *Node = new TreeNode(value); 36     if(root==NULL)                    // tree is empty 37       root = Node; 38     else { 39       TreeNode *parent; 40       TreeNode *tmpNode = root; 41       // Find the parent of "Node" 42       while(tmpNode!=NULL) {  43         parent = tmpNode; 44         if(tmpNode->val < Node->val)        // Node is in the right subtree 45           tmpNode = tmpNode->right; 46         else if(tmpNode->val > Node->val)    // Node is in the left subtree 47           tmpNode = tmpNode->left; 48         else                                // Node is in the middle subtree 49           tmpNode = tmpNode->middle; 50       } 51       // Insert the Node under parent 52       if(Node->val == parent->val) 53         parent->middle = Node; 54       else if(Node->val > parent->val) 55         parent->right = Node; 56       else 57         parent->left = Node; 58     } 59     return root; 60 } 61  62 // Method: Delete a node from tri-nary tree 63 // Return the root of new tree 64 TreeNode* trinaryTree:: deleteNode(TreeNode *root, int value) { 65          66     if(root==NULL) 67       return NULL; 68     if(root->val == value) { 69         if(root->left==NULL && root->middle==NULL && root->right==NULL) { // Delete a leaf 70             delete root; 71             return NULL; 72         } 73         if(root->middle!=NULL) {            // Middle child is not empty  74             root->middle = deleteNode(root->middle,value); 75         } 76         else { 77             if(root->left==NULL) {            // Left child is empty, but right child is not 78                 TreeNode* rightChild = root->right; 79                 delete root; 80                 return rightChild; 81                  82             } 83             else if(root->right==NULL) {    // Right child is empty, but left child is not 84                 TreeNode* leftChild = root->left; 85                 delete root; 86                 return leftChild; 87             } 88             else {    // Both left and right child exists 89                 TreeNode *successor = findSuccessor(root->right); 90                 root->val = successor->val; 91                 root->right = deleteNode(root->right,successor->val); 92             } 93         } 94     } 95     else if(root->val > value)  // Recursive left subtree 96       root->left = deleteNode(root->left,value); 97     else                        // Recursive right subtree 98       root->right = deleteNode(root->right,value); 99 100     return root;101 }102 103 // Method: Find the successor104 TreeNode* trinaryTree:: findSuccessor(TreeNode *root) {105     if(root->left==NULL)106       return root;107     else108       return findSuccessor(root->left);109 }110 111 112 // Method: Test113 bool trinaryTree:: test() {114     trinaryTree test;115     TreeNode *root = NULL;116     TreeNode *node;117     118     // Test tree insert119     int val[] = {5,4,9,5,7,2,2};120     int i;121     for(i=0;i<sizeof(val)/sizeof(int);i++) {122         root = test.insert(root,val[i]);123 124     }125     126     // Test tree delete127     // Case1: delete a leaf128     test.deleteNode(root,5);129     // Case2: delete root130     test.deleteNode(root,5);131     // Case3: delete a node with only left child132     test.deleteNode(root,4);133     134     return true;135 136 137 }

 

Implement insert and delete of Tri-nay tree