Find the Deepest Node in a Binary Tree
Last Updated :
15 Feb, 2023
Given a binary tree, find the deepest node in it.
Examples:
Input : Root of below tree
1
/ \
2 3
/ \ / \
4 5 6 7
\
8
Output : 8
Input : Root of below tree
1
/ \
2 3
/
6
Output : 6
Method 1: The idea is to do Inorder traversal of a given binary tree. While doing Inorder traversal, we pass level of current node also. We keep track of the maximum level seen so far and the value of the deepest node seen so far.
Implementation:
C++
// A C++ program to find value of the deepest node
// in a given binary tree
#include <bits/stdc++.h>
using namespace std;
// A tree node
struct Node
{
int data;
struct Node *left, *right;
};
// Utility function to create a new node
Node *newNode(int data)
{
Node *temp = new Node;
temp->data = data;
temp->left = temp->right = NULL;
return temp;
}
// maxLevel : keeps track of maximum level seen so far.
// res : Value of deepest node so far.
// level : Level of root
void find(Node *root, int level, int &maxLevel, int &res)
{
if (root != NULL)
{
find(root->left, ++level, maxLevel, res);
// Update level and rescue
if (level > maxLevel)
{
res = root->data;
maxLevel = level;
}
find(root->right, level, maxLevel, res);
}
}
// Returns value of deepest node
int deepestNode(Node *root)
{
// Initialize result and max level
int res = -1;
int maxLevel = -1;
// Updates value "res" and "maxLevel"
// Note that res and maxLen are passed
// by reference.
find(root, 0, maxLevel, res);
return res;
}
// Driver program
int main()
{
Node* root = newNode(1);
root->left = newNode(2);
root->right = newNode(3);
root->left->left = newNode(4);
root->right->left = newNode(5);
root->right->right = newNode(6);
root->right->left->right = newNode(7);
root->right->right->right = newNode(8);
root->right->left->right->left = newNode(9);
cout << deepestNode(root);
return 0;
}
// Java program to find value of the deepest node
// in a given binary tree
class GFG
{
// A tree node
static class Node
{
int data;
Node left, right;
Node(int key)
{
data = key;
left = null;
right = null;
}
}
static int maxLevel = -1;
static int res = -1;
// maxLevel : keeps track of maximum level seen so far.
// res : Value of deepest node so far.
// level : Level of root
static void find(Node root, int level)
{
if (root != null)
{
find(root.left, ++level);
// Update level and rescue
if (level > maxLevel)
{
res = root.data;
maxLevel = level;
}
find(root.right, level);
}
}
// Returns value of deepest node
static int deepestNode(Node root)
{
// Initialize result and max level
/* int res = -1;
int maxLevel = -1; */
// Updates value "res" and "maxLevel"
// Note that res and maxLen are passed
// by reference.
find(root, 0);
return res;
}
// Driver code
public static void main(String[] args)
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
System.out.println(deepestNode(root));
}
}
// This code is contributed by Princi Singh
"""Python3 program to find value of the
deepest node in a given binary tree"""
# A Binary Tree Node
# Utility function to create a
# new tree node
class newNode:
# Constructor to create a newNode
def __init__(self, data):
self.data= data
self.left = None
self.right = None
self.visited = False
# maxLevel : keeps track of maximum
# level seen so far.
# res : Value of deepest node so far.
# level : Level of root
def find(root, level, maxLevel, res):
if (root != None):
level += 1
find(root.left, level, maxLevel, res)
# Update level and rescue
if (level > maxLevel[0]):
res[0] = root.data
maxLevel[0] = level
find(root.right, level, maxLevel, res)
# Returns value of deepest node
def deepestNode(root) :
# Initialize result and max level
res = [-1]
maxLevel = [-1]
# Updates value "res" and "maxLevel"
# Note that res and maxLen are passed
# by reference.
find(root, 0, maxLevel, res)
return res[0]
# Driver Code
if __name__ == '__main__':
root = newNode(1)
root.left = newNode(2)
root.right = newNode(3)
root.left.left = newNode(4)
root.right.left = newNode(5)
root.right.right = newNode(6)
root.right.left.right = newNode(7)
root.right.right.right = newNode(8)
root.right.left.right.left = newNode(9)
print(deepestNode(root))
# This code is contributed by
# SHUBHAMSINGH10
// C# program to find value of the deepest node
// in a given binary tree
using System;
class GFG
{
// A tree node
public class Node
{
public int data;
public Node left, right;
public Node(int key)
{
data = key;
left = null;
right = null;
}
}
static int maxLevel = -1;
static int res = -1;
// maxLevel : keeps track of maximum level seen so far.
// res : Value of deepest node so far.
// level : Level of root
static void find(Node root, int level)
{
if (root != null)
{
find(root.left, ++level);
// Update level and rescue
if (level > maxLevel)
{
res = root.data;
maxLevel = level;
}
find(root.right, level);
}
}
// Returns value of deepest node
static int deepestNode(Node root)
{
// Initialize result and max level
/* int res = -1;
int maxLevel = -1; */
// Updates value "res" and "maxLevel"
// Note that res and maxLen are passed
// by reference.
find(root, 0);
return res;
}
// Driver code
public static void Main(String[] args)
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
Console.WriteLine(deepestNode(root));
}
}
// This code is contributed by 29AjayKumar
<script>
// JavaScript program to find value of the deepest node
// in a given binary tree
class Node
{
constructor(key)
{
this.data = key;
this.left = null;
this.right = null;
}
}
let maxLevel = -1;
let res = -1;
// maxLevel : keeps track of maximum level seen so far.
// res : Value of deepest node so far.
// level : Level of root
function find(root,level)
{
if (root != null)
{
find(root.left, ++level);
// Update level and rescue
if (level > maxLevel)
{
res = root.data;
maxLevel = level;
}
find(root.right, level);
}
}
// Returns value of deepest node
function deepestNode(root)
{
// Initialize result and max level
/* int res = -1;
int maxLevel = -1; */
// Updates value "res" and "maxLevel"
// Note that res and maxLen are passed
// by reference.
find(root, 0);
return res;
}
// Driver code
let root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
document.write(deepestNode(root));
// This code is contributed by rag2127
</script>
Time Complexity: O(n)
Auxiliary Space: O(n) for call stack
Method 2: The idea here is to find the height of the given tree and then print the node at the bottom-most level.
Implementation:
C++
// A C++ program to find value of the
// deepest node in a given binary tree
#include <bits/stdc++.h>
using namespace std;
// A tree node with constructor
class Node
{
public:
int data;
Node *left, *right;
// constructor
Node(int key)
{
data = key;
left = NULL;
right = NULL;
}
};
// Utility function to find height
// of a tree, rooted at 'root'.
int height(Node* root)
{
if(!root) return 0;
int leftHt = height(root->left);
int rightHt = height(root->right);
return max(leftHt, rightHt) + 1;
}
// levels : current Level
// Utility function to print all
// nodes at a given level.
void deepestNode(Node* root, int levels)
{
if(!root) return;
if(levels == 1)
cout << root->data;
else if(levels > 1)
{
deepestNode(root->left, levels - 1);
deepestNode(root->right, levels - 1);
}
}
// Driver program
int main()
{
Node* root = new Node(1);
root->left = new Node(2);
root->right = new Node(3);
root->left->left = new Node(4);
root->right->left = new Node(5);
root->right->right = new Node(6);
root->right->left->right = new Node(7);
root->right->right->right = new Node(8);
root->right->left->right->left = new Node(9);
// Calculating height of tree
int levels = height(root);
// Printing the deepest node
deepestNode(root, levels);
return 0;
}
// This code is contributed by decode2207.
// A Java program to find value of the
// deepest node in a given binary tree
class GFG
{
// A tree node with constructor
static class Node
{
int data;
Node left, right;
// constructor
Node(int key)
{
data = key;
left = null;
right = null;
}
};
// Utility function to find height
// of a tree, rooted at 'root'.
static int height(Node root)
{
if(root == null) return 0;
int leftHt = height(root.left);
int rightHt = height(root.right);
return Math.max(leftHt, rightHt) + 1;
}
// levels : current Level
// Utility function to print all
// nodes at a given level.
static void deepestNode(Node root,
int levels)
{
if(root == null) return;
if(levels == 1)
System.out.print(root.data + " ");
else if(levels > 1)
{
deepestNode(root.left, levels - 1);
deepestNode(root.right, levels - 1);
}
}
// Driver Codede
public static void main(String args[])
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
// Calculating height of tree
int levels = height(root);
// Printing the deepest node
deepestNode(root, levels);
}
}
// This code is contributed by Arnab Kundu
# A Python3 program to find value of the
# deepest node in a given binary tree
class new_Node:
def __init__(self, key):
self.data = key
self.left = self.right = None
# Utility function to find height
# of a tree, rooted at 'root'.
def height(root):
if(not root):
return 0
leftHt = height(root.left)
rightHt = height(root.right)
return max(leftHt, rightHt) + 1
# levels : current Level
# Utility function to print all
# nodes at a given level.
def deepestNode(root, levels):
if(not root):
return
if(levels == 1):
print(root.data)
elif(levels > 1):
deepestNode(root.left, levels - 1)
deepestNode(root.right, levels - 1)
# Driver Code
if __name__ == '__main__':
root = new_Node(1)
root.left = new_Node(2)
root.right = new_Node(3)
root.left.left = new_Node(4)
root.right.left = new_Node(5)
root.right.right = new_Node(6)
root.right.left.right = new_Node(7)
root.right.right.right = new_Node(8)
root.right.left.right.left = new_Node(9)
# Calculating height of tree
levels = height(root)
# Printing the deepest node
deepestNode(root, levels)
# This code is contributed by PranchalK
// C# program to find value of the
// deepest node in a given binary tree
using System;
class GFG
{
// A tree node with constructor
public class Node
{
public int data;
public Node left, right;
// constructor
public Node(int key)
{
data = key;
left = null;
right = null;
}
};
// Utility function to find height
// of a tree, rooted at 'root'.
static int height(Node root)
{
if(root == null) return 0;
int leftHt = height(root.left);
int rightHt = height(root.right);
return Math.Max(leftHt, rightHt) + 1;
}
// levels : current Level
// Utility function to print all
// nodes at a given level.
static void deepestNode(Node root,
int levels)
{
if(root == null) return;
if(levels == 1)
Console.Write(root.data + " ");
else if(levels > 1)
{
deepestNode(root.left, levels - 1);
deepestNode(root.right, levels - 1);
}
}
// Driver Code
public static void Main(String []args)
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
// Calculating height of tree
int levels = height(root);
// Printing the deepest node
deepestNode(root, levels);
}
}
/* This code contributed by PrinciRaj1992 */
<script>
// A Javascript program to find value of the
// deepest node in a given binary tree
// A tree node with constructor
class Node
{
// constructor
constructor(key)
{
this.data = key;
this.left = null;
this.right = null;
}
}
// Utility function to find height
// of a tree, rooted at 'root
function height(root)
{
if(root == null) return 0;
let leftHt = height(root.left);
let rightHt = height(root.right);
return Math.max(leftHt, rightHt) + 1;
}
// levels : current Level
// Utility function to print all
// nodes at a given level.
function deepestNode(root,levels)
{
if(root == null) return;
if(levels == 1)
document.write(root.data + " ");
else if(levels > 1)
{
deepestNode(root.left, levels - 1);
deepestNode(root.right, levels - 1);
}
}
// Driver Codede
let root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
// Calculating height of tree
let levels = height(root);
// Printing the deepest node
deepestNode(root, levels);
// This code is contributed by avanitrachhadiya2155
</script>
Time Complexity: O(n)
Space Complexity : O(n)
Method 3: The last node processed from the queue in level order is the deepest node in the binary tree.
Implementation:
C++
// A C++ program to find value of the
// deepest node in a given binary tree
#include <bits/stdc++.h>
using namespace std;
// A tree node with constructor
class Node
{
public:
int data;
Node *left, *right;
// constructor
Node(int key)
{
data = key;
left = NULL;
right = NULL;
}
};
// Function to return the deepest node
Node* deepestNode(Node* root)
{
Node* tmp = NULL;
if (root == NULL)
return NULL;
// Creating a Queue
queue<Node*> q;
q.push(root);
// Iterates until queue become empty
while (q.size() > 0)
{
tmp = q.front();
q.pop();
if (tmp->left != NULL)
q.push(tmp->left);
if (tmp->right != NULL)
q.push(tmp->right);
}
return tmp;
}
int main()
{
Node* root = new Node(1);
root->left = new Node(2);
root->right = new Node(3);
root->left->left = new Node(4);
root->right->left = new Node(5);
root->right->right = new Node(6);
root->right->left->right = new Node(7);
root->right->right->right = new Node(8);
root->right->left->right->left = new Node(9);
Node* deepNode = deepestNode(root);
cout << (deepNode->data);
return 0;
}
import java.util.*;
// A Java program to find value of the
// deepest node in a given binary tree
// A tree node with constructor
public class Node
{
int data;
Node left, right;
// constructor
Node(int key)
{
data = key;
left = null;
right = null;
}
};
class Gfg
{
// Function to return the deepest node
public static Node deepestNode(Node root)
{
Node tmp = null;
if (root == null)
return null;
// Creating a Queue
Queue<Node> q = new LinkedList<Node>();
q.offer(root);
// Iterates until queue become empty
while (!q.isEmpty())
{
tmp = q.poll();
if (tmp.left != null)
q.offer(tmp.left);
if (tmp.right != null)
q.offer(tmp.right);
}
return tmp;
}
public static void main(String[] args)
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
Node deepNode = deepestNode(root);
System.out.println(deepNode.data);
}
}
// Code is contributed by mahi_07
# A Python3 program to find value of the
# deepest node in a given binary tree by method 3
from collections import deque
class new_Node:
def __init__(self, key):
self.data = key
self.left = self.right = None
def deepestNode(root):
if root == None:
return 0
q = deque()
q.append(root)
node = None
while len(q) != 0:
node = q.popleft()
if node.left is not None:
q.append(node.left)
if node.right is not None:
q.append(node.right)
return node.data
# Driver Code
if __name__ == '__main__':
root = new_Node(1)
root.left = new_Node(2)
root.right = new_Node(3)
root.left.left = new_Node(4)
root.right.left = new_Node(5)
root.right.right = new_Node(6)
root.right.left.right = new_Node(7)
root.right.right.right = new_Node(8)
root.right.left.right.left = new_Node(9)
# Calculating height of tree
levels = deepestNode(root)
# Printing the deepest node
print(levels)
# This code is contributed by Aprajita Chhawi
// A C# program to find value of the
// deepest node in a given binary tree
using System;
using System.Collections.Generic;
// A tree node with constructor
public class Node
{
public
int data;
public
Node left, right;
// constructor
public
Node(int key)
{
data = key;
left = null;
right = null;
}
};
class Gfg
{
// Function to return the deepest node
public static Node deepestNode(Node root)
{
Node tmp = null;
if (root == null)
return null;
// Creating a Queue
Queue<Node> q = new Queue<Node>();
q.Enqueue(root);
// Iterates until queue become empty
while (q.Count != 0)
{
tmp = q.Peek();
q.Dequeue();
if (tmp.left != null)
q.Enqueue(tmp.left);
if (tmp.right != null)
q.Enqueue(tmp.right);
}
return tmp;
}
// Driver code
public static void Main(String[] args)
{
Node root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
Node deepNode = deepestNode(root);
Console.WriteLine(deepNode.data);
}
}
// This code is contributed by gauravrajput1
<script>
// A Javascript program to find value of the
// deepest node in a given binary tree
// A tree node with constructor
class Node
{
constructor(key)
{
this.data = key;
this.left = null;
this.right = null;
}
}
// Function to return the deepest node
function deepestNode(root)
{
let tmp = null;
if (root == null)
return null;
// Creating a Queue
let q = [];
q.push(root);
// Iterates until queue become empty
while (q.length!=0)
{
tmp = q.shift();
if (tmp.left != null)
q.push(tmp.left);
if (tmp.right != null)
q.push(tmp.right);
}
return tmp;
}
let root = new Node(1);
root.left = new Node(2);
root.right = new Node(3);
root.left.left = new Node(4);
root.right.left = new Node(5);
root.right.right = new Node(6);
root.right.left.right = new Node(7);
root.right.right.right = new Node(8);
root.right.left.right.left = new Node(9);
let deepNode = deepestNode(root);
document.write(deepNode.data);
// This code is contributed by unknown2108
</script>
Time Complexity: O(n)
Auxiliary Space: O(n)
Similar Reads
Find the closest leaf in a Binary Tree Given a Binary Tree and a key 'k', find distance of the closest leaf from 'k'. Examples: A / \ B C / \ E F / \ G H / \ / I J K Closest leaf to 'H' is 'K', so distance is 1 for 'H' Closest leaf to 'C' is 'B', so distance is 2 for 'C' Closest leaf to 'E' is either 'I' or 'J', so distance is 2 for 'E'
14 min read
Deepest left leaf node in a binary tree Given a Binary Tree, find the deepest leaf node that is left child of its parent. For example, consider the following tree. The deepest left leaf node is the node with value 9. 1 / \ 2 3 / / \ 4 5 6 \ \ 7 8 / \ 9 10 The idea is to recursively traverse the given binary tree and while traversing, main
13 min read
Find Minimum Depth of a Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. For example, minimum depth of below Binary Tree is 2. Note that the path must end on a leaf node. For example, the minimum depth of below Bi
15 min read
Depth of the deepest odd level node in Binary Tree Given a Binary tree, find out depth of the deepest odd level leaf node. Take root level as depth 1. Examples: Input : Output : 5Input : 10 / \ 28 13 / \ 14 15 / \ 23 24Output : 3We can traverse the tree starting from the root level and keep curr_level of the node. Increment the curr_level each time
13 min read
Closest leaf to a given node in Binary Tree Given a Binary Tree and a node x in it, find distance of the closest leaf to x in Binary Tree. If given node itself is a leaf, then distance is 0.Examples: Input: Root of below tree And x = pointer to node 13 10 / \ 12 13 / 14 Output 1 Distance 1. Closest leaf is 14. Input: Root of below tree And x
12 min read
Height and Depth of a node in a Binary Tree Given a Binary Tree consisting of n nodes and a integer k, the task is to find the depth and height of the node with value k in the Binary Tree.Note:The depth of a node is the number of edges present in path from the root node of a tree to that node. The height of a node is the maximum number of edg
15 min read
Replace node with depth in a binary tree Given a binary tree, replace each node with its depth value. For example, consider the following tree. Root is at depth 0, change its value to 0 and next level nodes are at depth 1 and so on. 3 0 / \ / \ 2 5 == >; 1 1 / \ / \ 1 4 2 2 The idea is to traverse tree starting from root. While traversi
11 min read
Find distance from root to given node in a binary tree Given the root of a binary tree and a key x in it, find the distance of the given key from the root. DisÂtance means the numÂber of edges between two nodes.Examples: Input: x = 45Input Binary TreeOutput: 3 Explanation: There are three edges on path from root to 45.For more understanding of question,
11 min read
Diameter of a Binary Indexed Tree with N nodes Given a Binary Indexed Tree with N nodes except root node 0 (Numbered from 1 to N), Find its diameter. Binary Indexed Tree is a tree where parent of a node number X = X - (X & (X - 1)) i.e. last bit is unset in X. The diameter of a tree is the longest simple path between any two leaves. Examples
7 min read