Package g2601_2700.s2641_cousins_in_binary_tree_ii

Class Solution

  • public class Solution
extends Object
    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 [1, 105].
    • 1 <= Node.val <= 104

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail