# Number of nodes greater than a given value in n-ary tree

Given a n-ary tree and a number x, find and return the number of nodes which are greater than x.

Example:

```In the given tree, x = 7 Number of nodes greater than x are 4.
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach :
The idea is maintain a count variable initialize to 0. Traverse the tree and compare root data with x. If root data is greater than x, increment the count variable and recursively call for all its children.

Below is the implementation of idea.

## C++

 `// C++ program to find number of nodes ` `// greater than x ` `#include ` `using` `namespace` `std; ` ` `  `// Structure of a node of n-ary tree ` `struct` `Node { ` `    ``int` `key; ` `    ``vector child; ` `}; ` ` `  `// Utility function to create ` `// a new tree node ` `Node* newNode(``int` `key) ` `{ ` `    ``Node* temp = ``new` `Node; ` `    ``temp->key = key; ` `    ``return` `temp; ` `} ` ` `  `// Function to find nuber of nodes ` `// gretaer than x ` `int` `nodesGreaterThanX(Node* root, ``int` `x) ` `{ ` `    ``if` `(root == NULL) ` `        ``return` `0; ` ` `  `    ``int` `count = 0; ` ` `  `    ``// if current root is greater ` `    ``// than x increment count ` `    ``if` `(root->key > x) ` `        ``count++; ` ` `  `    ``// Number of children of root ` `    ``int` `numChildren = root->child.size(); ` ` `  `    ``// recursively calling for every child ` `    ``for` `(``int` `i = 0; i < numChildren; i++) { ` `        ``Node* child = root->child[i]; ` `        ``count += nodesGreaterThanX(child, x); ` `    ``} ` ` `  `    ``// return the count ` `    ``return` `count; ` `} ` ` `  `// Driver program ` `int` `main() ` `{ ` `    ``/* Let us create below tree ` `*           5 ` `*         / | \ ` `*        1  2  3 ` `*       /  / \  \ ` `*     15  4   5  6 ` `*/` ` `  `    ``Node* root = newNode(5); ` `    ``(root->child).push_back(newNode(1)); ` `    ``(root->child).push_back(newNode(2)); ` `    ``(root->child).push_back(newNode(3)); ` `    ``(root->child->child).push_back(newNode(15)); ` `    ``(root->child->child).push_back(newNode(4)); ` `    ``(root->child->child).push_back(newNode(5)); ` `    ``(root->child->child).push_back(newNode(6)); ` ` `  `    ``int` `x = 5; ` ` `  `    ``cout << ``"Number of nodes greater than "` `         ``<< x << ``" are "``; ` `    ``cout << nodesGreaterThanX(root, x) ` `         ``<< endl; ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find number of nodes ` `// greater than x ` `import` `java.util.*; ` ` `  `// Class representing a Node of an N-ary tree ` `class` `Node{ ` `     `  `    ``int` `key;  ` `    ``ArrayList child;  ` ` `  `    ``// Constructor to create a Node ` `    ``Node(``int` `val) ` `    ``{ ` `        ``key = val; ` `        ``child = ``new` `ArrayList<>(); ` `    ``} ` `} ` ` `  `class` `GFG{ ` ` `  `// Recursive function to find number  ` `// of nodes greater than x ` `public` `static` `int` `nodesGreaterThanX(Node root, ``int` `x) ` `{ ` `    ``if` `(root == ``null``) ` `        ``return` `0``; ` ` `  `    ``int` `count = ``0``; ` ` `  `    ``// If current root is greater ` `    ``// than x increment count ` `    ``if` `(root.key > x) ` `        ``count++; ` ` `  `    ``// Recursively calling for every ` `    ``// child of current root ` `    ``for``(Node child : root.child) ` `    ``{ ` `        ``count += nodesGreaterThanX(child, x); ` `    ``} ` ` `  `    ``// Return the count ` `    ``return` `count; ` `} ` ` `  `// Driver code ` `public` `static` `void` `main(String[] args) ` `{ ` `     `  `    ``/* Let us create below tree  ` `            ``5  ` `          ``/ | \  ` `         ``1  2  3  ` `        ``/  / \  \  ` `      ``15  4   5  6  ` `    ``*/` `     `  `    ``Node root = ``new` `Node(``5``); ` `     `  `    ``root.child.add(``new` `Node(``1``)); ` `    ``root.child.add(``new` `Node(``2``)); ` `    ``root.child.add(``new` `Node(``3``)); ` `     `  `    ``root.child.get(``0``).child.add(``new` `Node(``15``)); ` `    ``root.child.get(``1``).child.add(``new` `Node(``4``)); ` `    ``root.child.get(``1``).child.add(``new` `Node(``5``)); ` `    ``root.child.get(``2``).child.add(``new` `Node(``6``)); ` ` `  `    ``int` `x = ``5``; ` ` `  `    ``System.out.print(``"Number of nodes greater than "` `+ ` `                     ``x + ``" are "``); ` `    ``System.out.println(nodesGreaterThanX(root, x)); ` `} ` `} ` ` `  `// This code is contributed by jrishabh99 `

## Python3

 `# Python program to find number of nodes ` `# greater than x ` ` `  `# Structure of a node of n-ary tree ` `class` `Node: ` `    ``def` `__init__(``self``, data): ` `        ``self``.key ``=` `data ` `        ``self``.child ``=` `[] ` ` `  `# Function to find nuber of nodes ` `# gretaer than x ` `def` `nodesGreaterThanX(root: Node, x: ``int``) ``-``> ``int``: ` `    ``if` `root ``is` `None``: ` `        ``return` `0` ` `  `    ``count ``=` `0` ` `  `    ``# if current root is greater ` `    ``# than x increment count ` `    ``if` `root.key > x: ` `        ``count ``+``=` `1` ` `  `    ``# Number of children of root ` `    ``numChildren ``=` `len``(root.child) ` ` `  `    ``# recursively calling for every child ` `    ``for` `i ``in` `range``(numChildren): ` `        ``child ``=` `root.child[i] ` `        ``count ``+``=` `nodesGreaterThanX(child, x) ` ` `  `    ``# return the count ` `    ``return` `count ` ` `  `# Driver Code ` `if` `__name__ ``=``=` `"__main__"``: ` ` `  `    ``ans ``=` `0` `    ``k ``=` `25` ` `  `    ``# Let us create below tree ` `    ``# 5 ` `    ``#         / | \ ` `    ``# 1  2  3 ` `    ``#       /  / \  \ ` `    ``# 15 4   5  6 ` ` `  `    ``root ``=` `Node(``5``) ` `    ``(root.child).append(Node(``1``)) ` `    ``(root.child).append(Node(``2``)) ` `    ``(root.child).append(Node(``3``)) ` `    ``(root.child[``0``].child).append(Node(``15``)) ` `    ``(root.child[``1``].child).append(Node(``4``)) ` `    ``(root.child[``1``].child).append(Node(``5``)) ` `    ``(root.child[``2``].child).append(Node(``6``)) ` ` `  `    ``x ``=` `5` ` `  `    ``print``(``"Number of nodes greater than % d are % d"` `%` `          ``(x, nodesGreaterThanX(root, x))) ` ` `  `# This code is contributed by ` `# sanjeev2552 `

Output:

```Number of nodes greater than 5 are 2
```

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Improved By : sanjeev2552, jrishabh99

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