剑指offer_二叉树---序列化二叉树

/**
 * 
 */
package 二叉树;
/**
 * <p>
 * Title:请实现两个函数，分别用来序列化和反序列化二叉树
 * 
 *
 */
public class SerializeAndDeserialize {
  /**
   * void
   * 
   * @param args
   */
  public String Serialize(TreeNode root) {    //通过前序遍历来序列化二叉树，遇到null值则改为特殊符号
    StringBuffer sb = new StringBuffer();
    if (root == null) {
      sb.append("#,");
      return sb.toString();
    }
    sb.append(root.val + ",");    //根
    sb.append(Serialize(root.left));//左
    sb.append(Serialize(root.right));//右
    return sb.toString();
  }
    public int index =-1;
  public TreeNode Deserialize(String str) {
    index++;
    int len = str.length();
    if(index>=len){       
      return null;    //index从0开始，到末尾结束
    }
    String[] strs = str.split(",");  //把字符串按照“，”分隔开
    TreeNode node =null;
    if(!strs[index].equals("#")){
      node = new TreeNode(Integer.valueOf(strs[index]));
      node.left =Deserialize(str);
      node.right = Deserialize(str);
    }
    return node;
  }
  public static void main(String[] args) {
    // TODO Auto-generated method stub
  }
}