437. Path Sum III

[Shawngbk]

/**

• Definition for a binary tree node.
• public class TreeNode {
• int val;
• TreeNode left;
• TreeNode right;
• TreeNode(int x) { val = x; }

• } */ public class Solution { int count = 0; public int pathSum(TreeNode root, int sum) { if(root != null) { dfs(root, sum); pathSum(root.left, sum); pathSum(root.right, sum); } return count; }

  private void dfs(TreeNode root, int sum) { if(root != null) { if(sum - root.val == 0) { count++; } dfs(root.left, sum - root.val); dfs(root.right, sum - root.val); } } }