Package g2601_2700.s2641_cousins_in_binary_tree_ii

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    2641 - Cousins in Binary Tree II.

    Medium

    Given the root of a binary tree, replace the value of each node in the tree with the sum of all its cousins' values.

    Two nodes of a binary tree are cousins if they have the same depth with different parents.

    Return the root of the modified tree.

    Note that the depth of a node is the number of edges in the path from the root node to it.

    Example 1:

    Input: root = 5,4,9,1,10,null,7

    Output: 0,0,0,7,7,null,11

    Explanation: The diagram above shows the initial binary tree and the binary tree after changing the value of each node.

    • Node with value 5 does not have any cousins so its sum is 0.

    • Node with value 4 does not have any cousins so its sum is 0.

    • Node with value 9 does not have any cousins so its sum is 0.

    • Node with value 1 has a cousin with value 7 so its sum is 7.

    • Node with value 10 has a cousin with value 7 so its sum is 7.

    • Node with value 7 has cousins with values 1 and 10 so its sum is 11.

    Example 2:

    Input: root = 3,1,2

    Output: 0,0,0

    Explanation: The diagram above shows the initial binary tree and the binary tree after changing the value of each node.

    • Node with value 3 does not have any cousins so its sum is 0.

    • Node with value 1 does not have any cousins so its sum is 0.

    • Node with value 2 does not have any cousins so its sum is 0.

    Constraints:

    • The number of nodes in the tree is in the range <code>1, 10<sup>5</sup></code>.

    • <code>1 <= Node.val <= 10<sup>4</sup></code>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final TreeNode replaceValueInTree(TreeNode root)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait