n叉树中大于给定值的节点数
给定一棵n叉树和一个数x ，找出并返回大于 x 的节点数。
例子：
In the given tree, x = 7
Number of nodes greater than x are 4.方法 ：
这个想法是保持一个计数变量初始化为0。遍历树并将根数据与x进行比较。如果根数据大于 x，则递增计数变量并递归调用其所有子项。
下面是idea的实现。
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 number of nodes
// greater 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[0]->child).push_back(newNode(15));
(root->child[1]->child).push_back(newNode(4));
(root->child[1]->child).push_back(newNode(5));
(root->child[2]->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
# Python3 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 number of nodes
# greater 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
# sanjeev2552C#
// C# program to find number of nodes
// greater than x
using System;
using System.Collections.Generic;
// Class representing a Node of an N-ary tree
public class Node
{
public int key;
public List child;
// Constructor to create a Node
public Node(int val)
{
key = val;
child = new List();
}
}
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
foreach(Node child in 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[0].child.Add(new Node(15));
root.child[1].child.Add(new Node(4));
root.child[1].child.Add(new Node(5));
root.child[2].child.Add(new Node(6));
int x = 5;
Console.Write("Number of nodes greater than " +
x + " are ");
Console.WriteLine(nodesGreaterThanX(root, x));
}
}
// This code is contributed by Amit Katiyar 输出：
Number of nodes greater than 5 are 2