题解 | #二维数组中的查找#

层序遍历Java实现

/*
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

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

    }

}
*/
import java.util.LinkedList;
public class Solution {
    String Serialize(TreeNode root) {
        if(root == null)
            return null;
        
        LinkedList<TreeNode> queue = new LinkedList();
        queue.add(root);
        String res = "{";
        boolean flag = true;
        while(flag){
            flag = false;
            int size = queue.size();
            for(int i=0; i<size; i++){
                TreeNode node = queue.poll();
                if(node == null){
                    if(i != size-1 || flag == true)
                        res = res + "#,";
                }else{
                    res = res + node.val + ",";
                    queue.add(node.left);
                    queue.add(node.right);
                    if(node.left != null || node.right != null)
                        flag = true;
                }
            }
        }
        return res.substring(0,res.length()-1).concat("}");
    }
    
    TreeNode Deserialize(String str) {
        System.out.println(str);
        if(str == null || "".equals(str))
            return null;
        
        String[] strs = str.replace("{","").replace("}","").split(",");
        LinkedList<TreeNode> queue = new LinkedList();
        TreeNode head = new TreeNode(Integer.parseInt(strs[0])); 
        queue.add(head);
        TreeNode node = null;
        int i = 1;
        while(i < strs.length){
            if(!queue.isEmpty())
                node = queue.poll();
            if(!"#".equals(strs[i++])){
                TreeNode newNode = new TreeNode(Integer.parseInt(strs[i-1]));
                node.left = newNode;
                queue.add(node.left);
            }
            if(i < strs.length && !"#".equals(strs[i++])){
                TreeNode newNode = new TreeNode(Integer.parseInt(strs[i-1]));
                node.right = newNode;
                queue.add(node.right);
            }
        }
        return head;
    }
}