Bottom-View.cpp

Successfully Added

Author: Manoj13-coder

Trees/Bottom-View.cpp

@@ -0,0 +1,100 @@
+// C++ Program to print Bottom View of Binary Tree 
+#include<bits/stdc++.h> 
+using namespace std; 
+
+// Tree node class 
+struct Node 
+{ 
+	int data; //data of the node 
+	int hd; //horizontal distance of the node 
+	Node *left, *right; //left and right references 
+
+	// Constructor of tree node 
+	Node(int key) 
+	{ 
+		data = key; 
+		hd = INT_MAX; 
+		left = right = NULL; 
+	} 
+}; 
+
+// Method that prints the bottom view. 
+void bottomView(Node *root) 
+{ 
+	if (root == NULL) 
+		return; 
+
+	// Initialize a variable 'hd' with 0 
+	// for the root element. 
+	int hd = 0; 
+
+	// TreeMap which stores key value pair 
+	// sorted on key value 
+	map<int, int> m; 
+
+	// Queue to store tree nodes in level 
+	// order traversal 
+	queue<Node *> q; 
+
+	// Assign initialized horizontal distance 
+	// value to root node and add it to the queue. 
+	root->hd = hd; 
+	q.push(root); // In STL, push() is used enqueue an item 
+
+	// Loop until the queue is empty (standard 
+	// level order loop) 
+	while (!q.empty()) 
+	{ 
+		Node *temp = q.front(); 
+		q.pop(); // In STL, pop() is used dequeue an item 
+
+		// Extract the horizontal distance value 
+		// from the dequeued tree node. 
+		hd = temp->hd; 
+
+		// Put the dequeued tree node to TreeMap 
+		// having key as horizontal distance. Every 
+		// time we find a node having same horizontal 
+		// distance we need to replace the data in 
+		// the map. 
+		m[hd] = temp->data; 
+
+		// If the dequeued node has a left child, add 
+		// it to the queue with a horizontal distance hd-1. 
+		if (temp->left != NULL) 
+		{ 
+			temp->left->hd = hd-1; 
+			q.push(temp->left); 
+		} 
+
+		// If the dequeued node has a right child, add 
+		// it to the queue with a horizontal distance 
+		// hd+1. 
+		if (temp->right != NULL) 
+		{ 
+			temp->right->hd = hd+1; 
+			q.push(temp->right); 
+		} 
+	} 
+
+	// Traverse the map elements using the iterator. 
+	for (auto i = m.begin(); i != m.end(); ++i) 
+		cout << i->second << " "; 
+} 
+
+// Driver Code 
+int main() 
+{ 
+	Node *root = new Node(20); 
+	root->left = new Node(8); 
+	root->right = new Node(22); 
+	root->left->left = new Node(5); 
+	root->left->right = new Node(3); 
+	root->right->left = new Node(4); 
+	root->right->right = new Node(25); 
+	root->left->right->left = new Node(10); 
+	root->left->right->right = new Node(14); 
+	cout << "Bottom view of the given binary tree :\n"
+	bottomView(root); 
+	return 0; 
+}