297.二叉树的序列化与反序列化.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/*
 * @lc app=leetcode.cn id=297 lang=java
 *
 * [297] 二叉树的序列化与反序列化
 */

// @lc code=start
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 * int val;
 * TreeNode left;
 * TreeNode right;
 * TreeNode(int x) { val = x; }
 * }
 */
class Codec {

    // Encodes a tree to a single string.
    public String serialize(TreeNode root) {
        if (root == null)
            return "#";
        return root.val + "," + serialize(root.left) + "," + serialize(root.right);
    }

    // Decodes your encoded data to tree.
    public TreeNode deserialize(String data) {
        String[] datas = data.split(",");
        ArrayList<String> nodes = new ArrayList<String>(Arrays.asList(datas));
        return deserialize(nodes);
    }

    private TreeNode deserialize(List<String> nodes) {
        if (nodes.isEmpty())
            return null;
        String val = nodes.remove(0);
        if (val.equals("#"))
            return null;
        TreeNode root = new TreeNode(Integer.parseInt(val));
        root.left = deserialize(nodes);
        root.right = deserialize(nodes);
        return root;
    }
}

// Your Codec object will be instantiated and called as such:
// Codec ser = new Codec();
// Codec deser = new Codec();
// TreeNode ans = deser.deserialize(ser.serialize(root));
// @lc code=end