题解 | #牛群的最大高度# Java 层序遍历

本以为是求最大高度, 没看清是最大的节点val

public class Solution {

    public int findMaxHeight (TreeNode root) {
        // 层序遍历
        if (root == null ) return 0;
        Queue<TreeNode> q = new LinkedList<>();
        q.offer(root);
        int ans = 0;
        while (!q.isEmpty()) {
            int size = q.size();
            for (int i = 0; i < size; i++) {
                TreeNode tmp = q.poll();
                ans = Math.max(ans, tmp.val);
                if (tmp.left != null) q.add(tmp.left);
                if (tmp.right != null) q.add(tmp.right);
            }
        }
        return ans;
    }
}