1609. Even Odd Tree
Medium
30 Points
Tree
Breadth-First Search
Binary Tree
A binary tree is named Even-Odd if it meets the following conditions:
Given the root of a binary tree, return true if the binary tree is Even-Odd, otherwise return false.
Examples
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
The number of nodes in the tree is in the range [1, 105].1 <= Node.val <= 106
1609. Even Odd Tree
Medium
30 Points
Tree
Breadth-First Search
Binary Tree
A binary tree is named Even-Odd if it meets the following conditions:
Given the root of a binary tree, return true if the binary tree is Even-Odd, otherwise return false.
Examples
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
The number of nodes in the tree is in the range [1, 105].1 <= Node.val <= 106