题解 | #序列化二叉树#

/*
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 "";
        }
        TreeNode node = root;
        StringBuffer sb = new StringBuffer();
        Deque<TreeNode> queue = new LinkedList<>();
        sb.append(node.val).append("#");
        queue.offer(node);
        while(!queue.isEmpty()){
            TreeNode cur = queue.poll();
            if(cur.left == null){
                sb.append("x").append("#");
            }else{
                sb.append(cur.left.val).append("#");
                queue.offer(cur.left);
            }
            if(cur.right == null){
               sb.append("x").append("#");
            }else{
                sb.append(cur.right.val).append("#");
                queue.offer(cur.right);
            }
        }
        return sb.toString();
    }
    TreeNode Deserialize(String str) {
        if(str == null || str.equals("")){
            return null;
        }
        String[] s = str.split("#");
        for(int j = 0;j < s.length;j ++){
            System.out.print(s[j]);
        }
 
        Deque<TreeNode> q = new LinkedList<>();
        TreeNode root = new TreeNode(Integer.parseInt(s[0]));
        q.offer(root);
        int i = 1;
        while(!q.isEmpty() && i < s.length){
            TreeNode node = q.poll();
             System.out.print(i);
             if(s[i].equals("x")){
                 node.left = null;
                 i++;
             }else{
                 node.left = new TreeNode(Integer.parseInt(s[i]));
                 q.offer(node.left);
                 i++;
             }
            if(s[i].equals("x")){
                 node.right = null;
                 i++;
             }else{
                 node.right = new TreeNode(Integer.parseInt(s[i]));
                 q.offer(node.right);
                 i++;
             }
        }
           return root; 
        
        }
}