二叉树中的最大父子总和

给定一棵二叉树，通过将父级与其子级相加来找到二叉树中的最大和。恰好需要添加三个节点。如果树中没有两个子节点都不为 NULL 的节点，则返回 0。

我们简单地遍历树并找到具有最大和的节点。我们需要照顾叶子。

C++

// C++ program to find maximum sum of a node
// and its children
#include 
using namespace std;
 
struct Node {
    int data;
    struct Node *left, *right;
};
 
 
// insertion of Node in Tree
struct Node* newNode(int n)
{
    struct Node* root = new Node();
    root->data = n;
    root->left = root->right = NULL;
    return root;
}
 
int maxSum(struct Node* root)
{
    if (root == NULL)
        return 0;
 
    int res = maxSum(root->left);
 
    // if left and right link are null then
    // add all the three Node
    if (root->left != NULL && root->right != NULL) {
        int sum = root->data + root->left->data + root->right->data;
        res = max(res, sum);
    }
 
    return max(res, maxSum(root->right));
}
 
int main()
{
    struct Node* root =  newNode(15);
    root->left = newNode(16);
    root->left->left = newNode(8);
    root->left->left->left = newNode(55);
    root->left->right = newNode(67);
    root->left->right->left = newNode(44);
    root->right = newNode(17);
    root->right->left = newNode(7);
    root->right->left->right = newNode(11);
    root->right->right = newNode(41);
    cout << maxSum(root);
    return 0;
}

Java

// Java program to find
// maximum sum of a node
// and its children
import java.util.*;
 
// insertion of Node in Tree
class Node
{
    int data;
    Node left, right;
     
     
    Node(int key)
    {
        data = key;
        left = right = null;
    }
}
class GFG
{
    public static int maxSum(Node root)
    {
        if (root == null)
        return 0;
 
    int res = maxSum(root.left);
 
    // if left and right link are null
    // then add all the three Node
    if (root.left != null &&
        root.right != null)
    {
        int sum = root.data +
                  root.left.data +
                  root.right.data;
        res = Math.max(res, sum);
    }
 
    return Math.max(res, maxSum(root.right));
    }
     
    // Driver code
    public static void main (String[] args)
    {
        Node root = new Node(15);
        root.left = new Node(16);
        root.left.right = new Node(67);
        root.left.right.left = new Node(44);
        root.left.left = new Node(8);
        root.left.left.left = new Node(55);
        root.right = new Node(17);
        root.right.right = new Node(41);
        root.right.left = new Node(7);
        root.right.left.right = new Node(11);
        System.out.print(maxSum(root));
    }
}
 
// This code is contributed
// by akash1295

Python3

# Python program to find maximum
# sum of a node and its children
class newNode():
 
    def __init__(self, data):
        self.data = data
        self.left = None
        self.right = None
 
def maxSum(root):
 
    if (root == None):
        return 0
 
    res = maxSum(root.left)
 
    # if left and right link are None then
    # add all the three Node
    if (root.left != None and root.right != None):
        sum = root.data + root.left.data + root.right.data
        res = max(res, sum)
 
    return max(res, maxSum(root.right))
     
# Driver code
if __name__ == '__main__':
    root = newNode(15)
    root.left = newNode(16)
    root.left.left = newNode(8)
    root.left.left.left = newNode(55)
    root.left.right = newNode(67)
    root.left.right.left = newNode(44)
    root.right = newNode(17)
    root.right.left = newNode(7)
    root.right.left.right = newNode(11)
    root.right.right = newNode(41)
    print(maxSum(root))
 
# This code is contributed by SHUBHAMSINGH10

C#

// C# program to find
// maximum sum of a node
// and its children
using System;
 
// insertion of Node in Tree
public class Node
{
    public int data;
    public Node left, right;
      
      
    public Node(int key)
    {
        data = key;
        left = right = null;
    }
}
public class GFG
{
    public static int maxSum(Node root)
    {
        if (root == null)
        return 0;
  
    int res = maxSum(root.left);
  
    // if left and right link are null
    // then add all the three Node
    if (root.left != null &&
        root.right != null)
    {
        int sum = root.data +
                  root.left.data +
                  root.right.data;
        res = Math.Max(res, sum);
    }
  
    return Math.Max(res, maxSum(root.right));
    }
      
    // Driver code
    public static void Main ()
    {
        Node root = new Node(15);
        root.left = new Node(16);
        root.left.right = new Node(67);
        root.left.right.left = new Node(44);
        root.left.left = new Node(8);
        root.left.left.left = new Node(55);
        root.right = new Node(17);
        root.right.right = new Node(41);
        root.right.left = new Node(7);
        root.right.left.right = new Node(11);
        Console.Write(maxSum(root));
    }
}
 
/* This code is contributed PrinciRaj1992 */

Javascript

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