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Path Sum

Given a binary tree (as a level-order array) and a target sum, return True if the tree has a root-to-leaf path where the values sum to the target.

Example:

Input:

5,4,8,11,null,13,4,7,2,null,null,null,1
22

Output:

True

Reasoning:

The binary tree is constructed from the level-order array: 5 is the root, 4 and 8 are its children, and so on.
We traverse all root-to-leaf paths, calculating their sums: $5 + 4 + 11 + 2 = 22$ , $5 + 4 + 11 + 1 = 21$ , $5 + 8 + 13 + 4 = 30$ , $5 + 8 + 13 + 7 = 33$ , $5 + 8 + 4 = 17$ , and $5 + 8 + 4 + 1 = 18$ .
Among these paths, one sum matches the target: $5 + 4 + 11 + 2 = 22$ .
Since a matching path is found, the function returns True.

Constraints:

0 <= number of nodes <= 5000
-1000 <= Node.val <= 1000
-1000 <= targetSum <= 1000

Editor

Python 3.13.1

Test Results

0/0

Run code to see test results.