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.<p>Medium</p> <p>Given the <code>root</code> of a binary tree and an integer <code>targetSum</code>, return <em>the number of paths where the sum of the values along the path equals</em> <code>targetSum</code>.</p> <p>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).</p> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2021/04/09/pathsum3-1-tree.jpg" alt="" /></p> <p><strong>Input:</strong> root = [10,5,-3,3,2,null,11,3,-2,null,1], targetSum = 8</p> <p><strong>Output:</strong> 3</p> <p><strong>Explanation:</strong> The paths that sum to 8 are shown.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> root = [5,4,8,11,null,13,4,7,2,null,null,5,1], targetSum = 22</p> <p><strong>Output:</strong> 3</p> <p><strong>Constraints:</strong></p> <ul> <li>The number of nodes in the tree is in the range <code>[0, 1000]</code>.</li> <li><code>-10⁹ <= Node.val <= 10⁹</code></li> <li><code>-1000 <= targetSum <= 1000</code></li> </ul>

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 Details

Solution

public Solution()

Method Details

pathSum

public int pathSum(TreeNode root,
 int targetSum)

helper

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