/
CousinsInBinaryTree.java
49 lines (42 loc) · 1.2 KB
/
CousinsInBinaryTree.java
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/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
// https://leetcode.com/problems/cousins-in-binary-tree
class Solution {
public boolean isCousins(TreeNode root, int x, int y) {
return depthOf(root, x) == depthOf(root, y) && parentOf(root, x) != parentOf(root, y);
}
int depthOf(TreeNode root, int x) {
if (root == null) {
return Integer.MIN_VALUE;
}
if (root.val == x) {
return 1;
}
return 1 + Math.max(depthOf(root.left, x), depthOf(root.right, x));
}
int parentOf(TreeNode root, int x) {
if (root == null) {
return -1;
}
if (root.left != null && root.left.val == x) {
return root.val;
}
if (root.right != null && root.right.val == x) {
return root.val;
}
return Math.max(parentOf(root.left, x), parentOf(root.right, x));
}
}