题解 | #二叉树的深度#

/**
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
import java.util.LinkedList;
import java.util.Queue;
public class Solution {
    public int TreeDepth(TreeNode root) {
        Queue<TreeNode> tree = new LinkedList<>();
        if (root != null) {
            tree.add(root);
        }
        int length = 0;
        while (!tree.isEmpty()) {
            int size = tree.size();
            while (size > 0) {
                TreeNode node = tree.peek();
                if (node.left != null) {
                    tree.add(node.left);
                }
                if (node.right != null) {
                    tree.add(node.right);
                }
                tree.remove(node);
                size--;
            }
            length++;
        }
        return length;
    }
}

解题思想：

* 方式一：递归左右子树

* 方式二：使用队列层次计算深度