Leetcode•May 16, 2025
Path Sum
Hazrat Ali
Leetcode
Given the root of a binary tree and an integer targetSum, return true if the tree has a root-to-leaf path such that adding up all the values along the path equals targetSum.
A leaf is a node with no children.
Example 1:
Input: root = [5,4,8,11,null,13,4,7,2,null,null,null,1], targetSum = 22 Output: true Explanation: The root-to-leaf path with the target sum is shown.
Example 2:
Input: root = [1,2,3], targetSum = 5 Output: false Explanation: There are two root-to-leaf paths in the tree: (1 --> 2): The sum is 3. (1 --> 3): The sum is 4. There is no root-to-leaf path with sum = 5.
Example 3:
Input: root = [], targetSum = 0 Output: false Explanation: Since the tree is empty, there are no root-to-leaf paths.
Solution
/**
* @param {TreeNode} root
* @param {number} sum
* @return {boolean}
*/
const hasPathSum = (root, sum) => {
if (!root) {
return false;
}
if (!root.left && !root.right) {
return root.val === sum;
}
return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val);
};