Even Odd Tree
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 index1, their children are at level index2, 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
1
/ \
10 4
/ / \
3 7 9
/ \ / \
12 8 6 2Input
root = [1,10,4,3,null,7,9,12,8,6,null,null,2]Output
trueLevels 0 and 2 contain odd values in strictly increasing order, and levels 1 and 3 contain even values in strictly decreasing order.
Example 2
5
/ \
4 2
/ \ /
3 3 7Input
root = [5,4,2,3,3,7]Output
falseLevel 2 contains values [3, 3, 7], which are not in strictly increasing order.
Constraints
- The number of nodes in the tree is in the range [1, 10^5].
- 1 <= Node.val <= 10^6