题解 | 序列化二叉树

层序遍历二叉树序列化与反序列化

import java.util.*;

public class Solution {
    String Serialize(TreeNode root) {
        if (root == null) {
            return "#";
        }
        StringBuilder res = new StringBuilder();
        LinkedList<TreeNode> queue = new LinkedList<TreeNode>();
        queue.add(root);
        while (!queue.isEmpty()) {
            TreeNode node = queue.removeFirst();
            if (node == null) {
                res.append("#,");
            } else {
                res.append(node.val).append(",");
                queue.add(node.left);
                queue.add(node.right);
            }
        }
        return res.toString();
    }

    TreeNode Deserialize(String str) {
        if (str.equals("#")) {
            return null;
        }
        String[] strs = str.split(",");
        TreeNode root = new TreeNode(Integer.parseInt(strs[0]));
        LinkedList<TreeNode> queue = new LinkedList<TreeNode>();
        queue.add(root);
        int i = 1;
        while (!queue.isEmpty()) {
            TreeNode node = queue.removeFirst();
            if (!strs[i].equals("#")) {
                node.left = new TreeNode(Integer.parseInt(strs[i]));
                queue.add(node.left);
            }
            i++;
            if (!strs[i].equals("#")) {
                node.right = new TreeNode(Integer.parseInt(strs[i]));
                queue.add(node.right);
            }
            i++;
        }
        return root;
    }
}