java.lang.Object

g1601_1700.s1609_even_odd_tree.Solution

public class Solution extends java.lang.Object

1609 - Even Odd Tree.

Medium

A binary tree is named Even-Odd if it meets the following conditions:

The root of the binary tree is at level index 0, its children are at level index 1, their children are at level index 2, etc.
For every even-indexed level, all nodes at the level have odd integer values in strictly increasing order (from left to right).
For every odd-indexed level, all nodes at the level have even integer values in strictly decreasing order (from left to right).

Given the root of a binary tree, return true if the binary tree is Even-Odd , otherwise return false.

Example 1:

Input: root = [1,10,4,3,null,7,9,12,8,6,null,null,2]

Output: true

Explanation: The node values on each level are:

Level 0: [1]

Level 1: [10,4]

Level 2: [3,7,9]

Level 3: [12,8,6,2]

Since levels 0 and 2 are all odd and increasing and levels 1 and 3 are all even and decreasing, the tree is Even-Odd.

Example 2:

Input: root = [5,4,2,3,3,7]

Output: false

Explanation: The node values on each level are:

Level 0: [5]

Level 1: [4,2]

Level 2: [3,3,7]

Node values in level 2 must be in strictly increasing order, so the tree is not Even-Odd.

Example 3:

Input: root = [5,9,1,3,5,7]

Output: false

Explanation: Node values in the level 1 should be even integers.

Constraints:

Class Solution

Constructor Summary