1022. Sum of Root To Leaf Binary Numbers

/**
 * Problem: LeetCode 1022 - Sum of Root To Leaf Binary Numbers
 * Difficulty: Easy
 * Language: Java
 * Author: CodeByTushu
 */
/**
 * 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 sumRootToLeaf(TreeNode root) {
        return dfs(root, 0);
    }

    private int dfs(TreeNode node, int current) {
        if (node == null) {
            return 0;
        }

        current = (current << 1) | node.val;

        // Leaf node reached
        if (node.left == null && node.right == null) {
            return current;
        }

        return dfs(node.left, current) + dfs(node.right, current);
    }
}

"""
Problem: LeetCode 1022 - Sum of Root To Leaf Binary Numbers
Difficulty: Easy
Language: Python
Author: CodeByTushu
"""
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 sumRootToLeaf(self, root: Optional[TreeNode]) -> int:
        def dfs(node: Optional[TreeNode], current: int) -> int:
            if not node:
                return 0

            current = (current << 1) | node.val

            if not node.left and not node.right:
                return current

            return dfs(node.left, current) + dfs(node.right, current)

        return dfs(root, 0)

/**
 * Problem: LeetCode 1022 - Sum of Root To Leaf Binary Numbers
 * Difficulty: Easy
 * Language: C++
 * Author: CodeByTushu
 */
/**
 * 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 sumRootToLeaf(TreeNode* root) {
        return dfs(root, 0);
    }

private:
    int dfs(TreeNode* node, int current) {
        if (!node) {
            return 0;
        }

        current = (current << 1) | node->val;

        if (!node->left && !node->right) {
            return current;
        }

        return dfs(node->left, current) + dfs(node->right, current);
    }
};

/**
 * Problem: LeetCode 1022 - Sum of Root To Leaf Binary Numbers
 * Difficulty: Easy
 * 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 sumRootToLeaf = function(root) {
    function dfs(node, current) {
        if (!node) {
            return 0;
        }

        current = (current << 1) | node.val;

        if (!node.left && !node.right) {
            return current;
        }

        return dfs(node.left, current) + dfs(node.right, current);
    }

    return dfs(root, 0);
};