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| class Solution {
public boolean isEvenOddTree(TreeNode root) {
Queue<TreeNode> queue = new LinkedList<>();
queue.offer(root);
int level = 0;
while (!queue.isEmpty()) {
TreeNode pre = null;
for (int i = queue.size(); i > 0; i--) {
TreeNode node = queue.poll();
if (level == (node.val & 1)) {
return false;
}
if (pre != null) {
if (level == 0) {
if (node.val <= pre.val) {
return false;
}
} else {
if (node.val >= pre.val) {
return false;
}
}
}
if (node.left != null) {
queue.offer(node.left);
}
if (node.right != null) {
queue.offer(node.right);
}
pre = node;
}
level ^= 1;
}
return true;
}
}
|