序列化二叉樹（層次遍歷）

題目描述

請實現兩個函數，分別用來序列化和反序列化二叉樹

 

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Queue;
/*
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

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

    }

}
*/
public class Solution {

    String Serialize(TreeNode root) {
        StringBuilder sb=new StringBuilder();
        Queue<TreeNode> queue =new LinkedList<TreeNode>();
        if(root!=null){
        	queue.add(root);
        }
        while(!queue.isEmpty()){
        	TreeNode node=queue.poll();
        	if(node!=null){
        		queue.offer(node.left);
        		queue.offer(node.right);
        		sb.append(node.val+",");
        	}else{
        		sb.append("#"+",");
        	}
        }
        if(sb.length()!=0){
        	sb.deleteCharAt(sb.length()-1);
        }
        return sb.toString();
        
  }
    TreeNode Deserialize(String str) {
    	if(str==null || str.length()==0){
    		return null;
    	}
    	String[] nodes=str.split(",");
    	TreeNode[] treeNodes=new TreeNode[nodes.length];
    	for(int i=0;i<nodes.length;i++){
    		if(!nodes[i].equals("#")){
    			treeNodes[i]=new TreeNode(Integer.parseInt(nodes[i]));
    		}
    	}
    	int j=1;
    	for(int i=0;j<treeNodes.length;i++){
    		if(treeNodes[i]!=null){
    			treeNodes[i].left=treeNodes[j++];
    			treeNodes[i].right=treeNodes[j++];
    		}
    	}
    	return treeNodes[0];
  }
}