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