leetcode-solutions/solutions/0501-1000/0993-cousins-in-binary-tree.java at main · Avuvos/leetcode-solutions · GitHub

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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;
 *     }
 * }
 */
class Solution {
    public boolean isCousins(TreeNode root, int x, int y) {
        Queue<TreeNode> q = new LinkedList<>();
        q.offer(root);
        while (!q.isEmpty()) {
            boolean foundX = false;
            boolean foundY = false;
            int size = q.size();
            for (int i=0; i<size; i++) {
                TreeNode curr = q.poll();
                if (curr.left != null && curr.right != null) {
                    if (curr.left.val == x && curr.right.val == y ||
                       curr.left.val == y && curr.right.val == x) {
                        return false;
                    }
                }
                if (curr.val == x) foundX = true;
                if (curr.val == y) foundY = true;
                if (curr.left != null) q.offer(curr.left);
                if (curr.right != null) q.offer(curr.right);
            }
            if (foundX && foundY)
                return true;
        }
        return false;
    }
}