Count Non-Leaf nodes in a Binary Tree
Given a Binary tree, count total number of non-leaf nodes in the tree
Examples:
Input :Output :2 Explanation In the above tree only two nodes 1 and 2 are non-leaf nodes
We recursively traverse the given tree. While traversing, we count non-leaf nodes in left and right subtrees and add 1 to the result.
C++
// CPP program to count total number of // non-leaf nodes in a binary tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */struct Node { int data; struct Node* left; struct Node* right; }; /* Helper function that allocates a new node with the given data and NULL left and right pointers. */struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } /* Computes the number of non-leaf nodes in a tree. */int countNonleaf(struct Node* root) { // Base cases. if (root == NULL || (root->left == NULL && root->right == NULL)) return 0; // If root is Not NULL and its one of its // child is also not NULL return 1 + countNonleaf(root->left) + countNonleaf(root->right); } /* Driver program to test size function*/int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << countNonleaf(root); return 0; } |
Java
// Java program to count total number of // non-leaf nodes in a binary tree class GfG { /* A binary tree node has data, pointer to left child and a pointer to right child */static class Node { int data; Node left; Node right; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */static Node newNode(int data) { Node node = new Node(); node.data = data; node.left = null; node.right = null; return (node); } /* Computes the number of non-leaf nodes in a tree. */static int countNonleaf(Node root) { // Base cases. if (root == null || (root.left == null && root.right == null)) return 0; // If root is Not NULL and its one of its // child is also not NULL return 1 + countNonleaf(root.left) + countNonleaf(root.right); } /* Driver program to test size function*/public static void main(String[] args) { Node root = newNode(1); root.left = newNode(2); root.right = newNode(3); root.left.left = newNode(4); root.left.right = newNode(5); System.out.println(countNonleaf(root)); } } |
Python3
# Python3 program to count total number # of non-leaf nodes in a binary tree # class that allocates a new node with the #given data and None left and right pointers. class newNode: def __init__(self,data): self.data = data self.left = self.right = None # Computes the number of non-leaf # nodes in a tree. def countNonleaf(root): # Base cases. if (root == None or (root.left == None and root.right == None)): return 0 # If root is Not None and its one of # its child is also not None return (1 + countNonleaf(root.left) + countNonleaf(root.right)) # Driver Code if __name__ == '__main__': root = newNode(1) root.left = newNode(2) root.right = newNode(3) root.left.left = newNode(4) root.left.right = newNode(5) print(countNonleaf(root)) # This code is contributed by PranchalK |
C#
// C# program to count total number of // non-leaf nodes in a binary tree using System; class GfG { /* A binary tree node has data, pointer to left child and a pointer to right child */ class Node { public int data; public Node left; public Node right; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ static Node newNode(int data) { Node node = new Node(); node.data = data; node.left = null; node.right = null; return (node); } /* Computes the number of non-leaf nodes in a tree. */ static int countNonleaf(Node root) { // Base cases. if (root == null || (root.left == null && root.right == null)) return 0; // If root is Not NULL and its one of its // child is also not NULL return 1 + countNonleaf(root.left) + countNonleaf(root.right); } /* Driver code*/ public static void Main(String[] args) { Node root = newNode(1); root.left = newNode(2); root.right = newNode(3); root.left.left = newNode(4); root.left.right = newNode(5); Console.WriteLine(countNonleaf(root)); } } // This code is contributed by PrinciRaj1992 |
Output:
2
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
