BST operations

Author: dexterrxx31

insert_BST.cpp

@@ -4,25 +4,25 @@ using namespace std;
 struct Node
 {
     int data;
-    Node *left ;
+    Node *left;
     Node *right;
 };
 
-Node * newNode(int data)
+Node *newNode(int data)
 {
-    Node * new_node = new Node ;
-    new_node->data = data ;
-    new_node->left = NULL ;
-    new_node->right = NULL ;
-    return new_node ; 
+    Node *new_node = new Node;
+    new_node->data = data;
+    new_node->left = NULL;
+    new_node->right = NULL;
+    return new_node;
 }
 
 Node *create_BST(int arr[], int n, int i)
 {
     Node *root = nullptr;
 
     if (i < n)
-    {   
+    {
         root = newNode(arr[i]);
         root->left = create_BST(arr, n, 2 * i + 1);
         root->right = create_BST(arr, n, 2 * i + 2);
@@ -32,43 +32,64 @@ Node *create_BST(int arr[], int n, int i)
 
 void inorder_traversal(Node *root)
 {
-    if(root != NULL)
+    if (root != NULL)
     {
         inorder_traversal(root->left);
-        cout<<root->data<<" ";
+        cout << root->data << " ";
         inorder_traversal(root->right);
     }
 }
 
-//insert element in BST 
-Node * insert_BST(Node * root , int e)
-{   
+// insert element in BST
+Node *insert_BST_recursion(Node *root, int e)
+{
 
-    if(!root)
+    if (!root)
     {
-        Node * node = new Node ;
+        Node *node = new Node;
         node = newNode(e);
-        return node ; 
+        return node;
+    }
+    if (root->data > e)
+        root->left = insert_BST(root->left, e);
+    
+    else if (root->data < e)
+        root->right = insert_BST(root->right, e);
+
+    return root;
+}
+
+void insert_BST_iteration(Node *root, int e)
+{
+    Node *prev = nullptr;
+    while (root != nullptr)
+    {
+        prev = root;
+        if( root->data == e)
+            return ;
+        if (root->data > e)
+            root = root->left ;
+        
+        else if (root->data < e)
+            root = root->right ;
     }
-        if(root->data > e)
-        {
-            root->left = insert_BST(root->left , e );
-        }
-        else if(root->data < e)
-        {
-            root->right = insert_BST(root->right , e);
-        }
-    return root ;    
+
+    Node * node = newNode(e) ;
+    if(prev->data > e)
+       prev->left = node ; 
+    else 
+        prev->right = node ;
 }
 
 int main()
 {
     int arr[] = {30, 20, 40, 10, 25, 35, 50};
     int n = sizeof(arr) / sizeof(arr[0]);
-    Node * root = create_BST(arr, n ,0);
+    Node *root = create_BST(arr, n, 0);
     inorder_traversal(root);
-    root  = insert_BST(root , 45);
-    cout<<endl;
+    //root = insert_BST_recursion(root, 45);
+    insert_BST_iteration(root , 45) ;
+    cout << endl;
     inorder_traversal(root);
     return 0;
 }