Find maximum level sum in Binary Tree

// A queue based C# program to find maximum 
// sum of a level in Binary Tree
using System;
using System.Collections.Generic;
class GFG
{

  // A binary tree node has data, pointer
  // to left child and a pointer to right
  // child
  public
    class Node 
    {
      public
        int data;
      public
        Node left, right;

      public Node(int data)
      {
        this.data = data;
        this.left = this.right = null;
      }
    };

  // Function to find the maximum 
  // sum of a level in tree
  // using level order traversal
  static int maxLevelSum(Node root) 
  {

    // Base case
    if (root == null)
      return 0;

    // Initialize result
    int result = root.data;

    // Do Level order traversal keeping
    // track of number of nodes at every
    // level.
    Queue<Node> q = new Queue<Node>();
    q.Enqueue(root);
    while (q.Count != 0) 
    {

      // Get the size of queue when the
      // level order traversal for one
      // level finishes
      int count = q.Count;

      // Iterate for all the nodes
      // in the queue currently
      int sum = 0;
      while (count --> 0)
      {

        // Dequeue an node from queue
        Node temp = q.Dequeue();

        // Add this node's value 
        // to current sum.
        sum = sum + temp.data;

        // Enqueue left and right children
        // of dequeued node
        if (temp.left != null)
          q.Enqueue(temp.left);
        if (temp.right != null)
          q.Enqueue(temp.right);
      }

      // Update the maximum node
      // count value
      result = Math.Max(sum, result);
    }
    return result;
  }

  // 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.left.right = new Node(5);
    root.right.right = new Node(8);
    root.right.right.left = new Node(6);
    root.right.right.right = new Node(7);

    /*   Constructed Binary tree is:
                 1
               /   \
             2      3
           /  \      \
          4    5      8
                    /   \
                   6     7    */
    Console.WriteLine("Maximum level sum is " +
                      maxLevelSum(root));
  }
}

// This code is contributed by gauravrajput1

using System;
using System.Collections.Generic;

class Node
{
    public int data;
    public Node left, right;

    public Node(int item)
    {
        data = item;
        left = right = null;
    }
}

public class MainClass
{
    // Function to get sum of each level
    static void DFS(Node root, int level, Dictionary<int, int> mm)
    {
        // Base condition
        if (root == null)
            return;

        // Adding root value to its level sum
        if (mm.ContainsKey(level))
            mm[level] += root.data;
        else
            mm[level] = root.data;

        // Increasing level
        level++;

        // Moving left
        DFS(root.left, level, mm);

        // Moving right
        DFS(root.right, level, mm);
    }

    // Function to find the maximum sum of a level in the tree
    static int MaxLevelSum(Node root)
    {
        // Base case
        if (root == null)
            return 0;

        // Dictionary to store the sum of each level
        Dictionary<int, int> mm = new Dictionary<int, int>();

        // Calling the function to calculate the sum of each level
        DFS(root, 0, mm);

        // Variable to store the answer
        int result = int.MinValue;

        // Iterating over the dictionary to find the maximum sum
        foreach (var val in mm.Values)
        {
            result = Math.Max(result, val);
        }

        return result;
    }

    // Helper function to allocate a new node with the given data and NULL left and right pointers
    static Node NewNode(int data)
    {
        Node node = new Node(data);
        return node;
    }

    // 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);
        root.right.right = NewNode(8);
        root.right.right.left = NewNode(6);
        root.right.right.right = NewNode(7);

        /* Constructed Binary tree is:
                1
            / \
            2     3
        / \     \
        4 5     8
                    / \
                6     7 */
        Console.WriteLine("Maximum level sum is " + MaxLevelSum(root));
    }
}