Watch 10 video solutions for Path Sum III, a medium level problem involving Tree, Depth-First Search, Binary Tree. This walkthrough by NeetCode has 78,794 views views. Want to try solving it yourself? Practice on FleetCode or read the detailed text solution.
Given the root of a binary tree and an integer targetSum, return the number of paths where the sum of the values along the path equals targetSum.
The path does not need to start or end at the root or a leaf, but it must go downwards (i.e., traveling only from parent nodes to child nodes).
Example 1:
Input: root = [10,5,-3,3,2,null,11,3,-2,null,1], targetSum = 8 Output: 3 Explanation: The paths that sum to 8 are shown.
Example 2:
Input: root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22 Output: 3
Constraints:
[0, 1000].-109 <= Node.val <= 109-1000 <= targetSum <= 1000