Create Deletion in Binary Tree

Author: soumyaawasthi05

Tree/Deletion in Binary Tree

@@ -0,0 +1,137 @@
+// C++ program to delete element in binary tree 
+#include <bits/stdc++.h> 
+using namespace std; 
+
+/* A binary tree node has key, pointer to left 
+child and a pointer to right child */
+struct Node { 
+	int key; 
+	struct Node *left, *right; 
+}; 
+
+/* function to create a new node of tree and 
+return pointer */
+struct Node* newNode(int key) 
+{ 
+	struct Node* temp = new Node; 
+	temp->key = key; 
+	temp->left = temp->right = NULL; 
+	return temp; 
+}; 
+
+/* Inorder traversal of a binary tree*/
+void inorder(struct Node* temp) 
+{ 
+	if (!temp) 
+		return; 
+	inorder(temp->left); 
+	cout << temp->key << " "; 
+	inorder(temp->right); 
+} 
+
+/* function to delete the given deepest node 
+(d_node) in binary tree */
+void deletDeepest(struct Node* root, 
+				struct Node* d_node) 
+{ 
+	queue<struct Node*> q; 
+	q.push(root); 
+
+	// Do level order traversal until last node 
+	struct Node* temp; 
+	while (!q.empty()) { 
+		temp = q.front(); 
+		q.pop(); 
+		if (temp == d_node) { 
+			temp = NULL; 
+			delete (d_node); 
+			return; 
+		} 
+		if (temp->right) { 
+			if (temp->right == d_node) { 
+				temp->right = NULL; 
+				delete (d_node); 
+				return; 
+			} 
+			else
+				q.push(temp->right); 
+		} 
+
+		if (temp->left) { 
+			if (temp->left == d_node) { 
+				temp->left = NULL; 
+				delete (d_node); 
+				return; 
+			} 
+			else
+				q.push(temp->left); 
+		} 
+	} 
+} 
+
+/* function to delete element in binary tree */
+Node* deletion(struct Node* root, int key) 
+{ 
+	if (root == NULL) 
+		return NULL; 
+
+	if (root->left == NULL && root->right == NULL) { 
+		if (root->key == key) 
+			return NULL; 
+		else
+			return root; 
+	} 
+
+	queue<struct Node*> q; 
+	q.push(root); 
+
+	struct Node* temp; 
+	struct Node* key_node = NULL; 
+
+	// Do level order traversal to find deepest 
+	// node(temp) and node to be deleted (key_node) 
+	while (!q.empty()) { 
+		temp = q.front(); 
+		q.pop(); 
+
+		if (temp->key == key) 
+			key_node = temp; 
+
+		if (temp->left) 
+			q.push(temp->left); 
+
+		if (temp->right) 
+			q.push(temp->right); 
+	} 
+
+	if (key_node != NULL) { 
+		int x = temp->key; 
+		deletDeepest(root, temp); 
+		key_node->key = x; 
+	} 
+	return root; 
+} 
+
+// Driver code 
+int main() 
+{ 
+	struct Node* root = newNode(10); 
+	root->left = newNode(11); 
+	root->left->left = newNode(7); 
+	root->left->right = newNode(12); 
+	root->right = newNode(9); 
+	root->right->left = newNode(15); 
+	root->right->right = newNode(8); 
+
+	cout << "Inorder traversal before deletion : "; 
+	inorder(root); 
+
+	int key = 11; 
+	root = deletion(root, key); 
+
+	cout << endl; 
+	cout << "Inorder traversal after deletion : "; 
+	inorder(root); 
+
+	return 0; 
+}