Problem Statement

Given the root of a binary tree with unique values and two different nodes x and y, return a boolean value based on whether the nodes corresponding to the values x and y are cousins.

Two nodes are cousins if they are at the same depth but have different parents.

Examples

Example 1:

• Input: root = [1, 2, 3, 4, null, 5, 6], x = 4, y = 5

    1
   / \
  2   3
 /   / \
4   5   6  

• Expected Output: true
• Justification: Nodes 4 and 5 both are at depth 2 with parent 2. They are cousins because their parents are different and they are at the same depth.

Example 2:

• Input: root = [1, 2, 3, 4, 5, null, null, null, null, 6, 7], x = 6, y = 7

    1
   / \
  2   3
 / \  
4   5   
   / \
  6   7

• Expected Output: false
• Justification: Both nodes 6 and 7 are at depth 3, but they have the same parent 5.

Example 3:

• Input: root = [1, 2, 3, null, 4, 5, null], x = 4, y = 5

    1
  /  \
 2    3
  \   /
   4 5

• Expected Output: true
• Justification: Node 4 is at depth 2 with parent 2. Node 5 is at depth 2 with parent 3. Both nodes are at the same depth but have different parents.

Try it yourself

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