剑指offer(61)二叉树的序列化与反序列化
一 先序遍历
/*
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) {
if(root == null){
return "#!";
}
String res = head.val + "!";
res += Serialize(root.left);
res += Serialize(root.right);
return res;
}
TreeNode Deserialize(String str) {
String[] values = str.split("!");
Queue<String> queue = new LinkedList<String>();
for(int i = 0;i != values.length;i++){
queue.offer(values[i]);
}
return DeserializeHelp(queue);
}
public TreeNode DeserializeHelp(Queue<String> queue){
String value = queue.poll();
if(value.equals("#")){
return null;
}
TreeNode head = new TreeNode(Integer.valueOf(value));
head.left = DeserializeHelp(queue);
head.right = DeserializeHelp(queue);
return head;
}
}
二 层序遍历(左程云《程序员面试宝典》P106