1161. Maximum Level Sum of a Binary Tree

/**
 * Problem: LeetCode 1161 - Maximum Level Sum of a Binary Tree
 * Difficulty: Medium
 * Language: Java
 * Author: CodeByTushu
 */
import java.util.ArrayDeque;
import java.util.Queue;

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public int maxLevelSum(TreeNode root) {
        if (root == null) {
            return 0;
        }

        int maxSum = Integer.MIN_VALUE;
        int maxLevel = 1;
        int currentLevel = 1;

        Queue<TreeNode> queue = new ArrayDeque<>();
        queue.offer(root);

        while (!queue.isEmpty()) {
            int levelSize = queue.size();
            int levelSum = 0;

            for (int i = 0; i < levelSize; i++) {
                TreeNode node = queue.poll();
                levelSum += node.val;

                if (node.left != null) {
                    queue.offer(node.left);
                }
                if (node.right != null) {
                    queue.offer(node.right);
                }
            }

            if (levelSum > maxSum) {
                maxSum = levelSum;
                maxLevel = currentLevel;
            }

            currentLevel++;
        }

        return maxLevel;
    }
}

"""
Problem: LeetCode 1161 - Maximum Level Sum of a Binary Tree
Difficulty: Medium
Language: Python
Author: CodeByTushu
"""
from collections import deque
from typing import Optional

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right

class Solution:
    def maxLevelSum(self, root: Optional[TreeNode]) -> int:
        if not root:
            return 0

        max_sum = float('-inf')
        max_level = 1
        current_level = 1

        queue = deque([root])

        while queue:
            level_sum = 0
            for _ in range(len(queue)):
                node = queue.popleft()
                level_sum += node.val

                if node.left:
                    queue.append(node.left)
                if node.right:
                    queue.append(node.right)

            if level_sum > max_sum:
                max_sum = level_sum
                max_level = current_level

            current_level += 1

        return max_level

/**
 * Problem: LeetCode 1161 - Maximum Level Sum of a Binary Tree
 * Difficulty: Medium
 * Language: C++
 * Author: CodeByTushu
 */
#include <queue>
#include <climits>

using namespace std;

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    int maxLevelSum(TreeNode* root) {
        if (!root) {
            return 0;
        }

        int maxSum = INT_MIN;
        int maxLevel = 1;
        int currentLevel = 1;

        queue<TreeNode*> q;
        q.push(root);

        while (!q.empty()) {
            int levelSize = q.size();
            int levelSum = 0;

            for (int i = 0; i < levelSize; ++i) {
                TreeNode* node = q.front();
                q.pop();
                levelSum += node->val;

                if (node->left) {
                    q.push(node->left);
                }
                if (node->right) {
                    q.push(node->right);
                }
            }

            if (levelSum > maxSum) {
                maxSum = levelSum;
                maxLevel = currentLevel;
            }

            currentLevel++;
        }

        return maxLevel;
    }
};

/**
 * Problem: LeetCode 1161 - Maximum Level Sum of a Binary Tree
 * Difficulty: Medium
 * Language: JavaScript
 * Author: CodeByTushu
 */
/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var maxLevelSum = function(root) {
    if (!root) {
        return 0;
    }

    let maxSum = -Infinity;
    let maxLevel = 1;
    let currentLevel = 1;

    const queue = [root];

    while (queue.length > 0) {
        const levelSize = queue.length;
        let levelSum = 0;

        for (let i = 0; i < levelSize; i++) {
            const node = queue.shift();
            levelSum += node.val;

            if (node.left) {
                queue.push(node.left);
            }
            if (node.right) {
                queue.push(node.right);
            }
        }

        if (levelSum > maxSum) {
            maxSum = levelSum;
            maxLevel = currentLevel;
        }

        currentLevel++;
    }

    return maxLevel;
};