java.lang.Object
g1401_1500.s1457_pseudo_palindromic_paths_in_a_binary_tree.Solution

public class Solution extends Object
1457 - Pseudo-Palindromic Paths in a Binary Tree\. Medium Given a binary tree where node values are digits from 1 to 9. A path in the binary tree is said to be **pseudo-palindromic** if at least one permutation of the node values in the path is a palindrome. _Return the number of **pseudo-palindromic** paths going from the root node to leaf nodes._ **Example 1:** ![](https://assets.leetcode.com/uploads/2020/05/06/palindromic_paths_1.png) **Input:** root = [2,3,1,3,1,null,1] **Output:** 2 **Explanation:** The figure above represents the given binary tree. There are three paths going from the root node to leaf nodes: the red path [2,3,3], the green path [2,1,1], and the path [2,3,1]. Among these paths only red path and green path are pseudo-palindromic paths since the red path [2,3,3] can be rearranged in [3,2,3] (palindrome) and the green path [2,1,1] can be rearranged in [1,2,1] (palindrome). **Example 2:** **![](https://assets.leetcode.com/uploads/2020/05/07/palindromic_paths_2.png)** **Input:** root = [2,1,1,1,3,null,null,null,null,null,1] **Output:** 1 **Explanation:** The figure above represents the given binary tree. There are three paths going from the root node to leaf nodes: the green path [2,1,1], the path [2,1,3,1], and the path [2,1]. Among these paths only the green path is pseudo-palindromic since [2,1,1] can be rearranged in [1,2,1] (palindrome). **Example 3:** **Input:** root = [9] **Output:** 1 **Constraints:** * The number of nodes in the tree is in the range [1, 105]. * `1 <= Node.val <= 9`
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • pseudoPalindromicPaths

      public int pseudoPalindromicPaths(TreeNode root)