Package g0401_0500.s0437_path_sum_iii

Class Solution

java.lang.Object

g0401_0500.s0437_path_sum_iii.Solution

public class Solution
extends Object

437 - Path Sum III.

Medium

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:

• The number of nodes in the tree is in the range [0, 1000].
• -109 <= Node.val <= 109
• -1000 <= targetSum <= 1000

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
void	helper(TreeNode node, int targetSum, long currSum)
int	pathSum(TreeNode root, int targetSum)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

pathSum

public int pathSum(TreeNode root,
                   int targetSum)

helper

public void helper(TreeNode node,
                   int targetSum,
                   long currSum)