标签：arc tran member public cal variable int order obj
Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another computer environment.
Design an algorithm to serialize and deserialize a binary search tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary search tree can be serialized to a string and this string can be deserialized to the original tree structure.
The encoded string should be as compact as possible.
Note: Do not use class member/global/static variables to store states. Your serialize and deserialize algorithms should be stateless.
serialize用preorder traverse，deserialize用queue作辅助，左右分别递归
serialize -- time: O(n), space: O(height)
deserialize -- time: O(n), space: O(n)
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Codec { // Encodes a tree to a single string. public String serialize(TreeNode root) { if(root == null) { return ""; } StringBuilder sb = new StringBuilder(); preorder(root, sb); return sb.toString(); } public void preorder(TreeNode root, StringBuilder sb) { if(root == null) { return; } sb.append(root.val).append(" "); preorder(root.left, sb); preorder(root.right, sb); } // Decodes your encoded data to tree. public TreeNode deserialize(String data) { if(data == "") { return null; } String[] vals = data.split(" "); Queue<Integer> q = new LinkedList<>(); for(String val : vals) { q.offer(Integer.parseInt(val)); } return deserialize(q); } public TreeNode deserialize(Queue<Integer> q) { if(q.isEmpty()) { return null; } TreeNode root = new TreeNode(q.poll()); Queue<Integer> smallerQ = new LinkedList<>(); while(!q.isEmpty() && q.peek() < root.val) { smallerQ.offer(q.poll()); } root.left = deserialize(smallerQ); root.right = deserialize(q); return root; } } // Your Codec object will be instantiated and called as such: // Codec codec = new Codec(); // codec.deserialize(codec.serialize(root));
449. Serialize and Deserialize BST - Medium
标签：arc tran member public cal variable int order obj
原文地址：https://www.cnblogs.com/fatttcat/p/10202259.html
