375 -二叉树的克隆

4.1

没啥感觉，呵呵

就是用递归啊

非递归的懒得写，我真的是懒。

/**
 * Definition of TreeNode:
 * public class TreeNode {
 *     public int val;
 *     public TreeNode left, right;
 *     public TreeNode(int val) {
 *         this.val = val;
 *         this.left = this.right = null;
 *     }
 * }
 */
public class Solution {
    /**
     * @param root: The root of binary tree
     * @return root of new tree
     */

    public TreeNode cloneTree(TreeNode root) {
        if(root == null){
            return root;
        }
        TreeNode newRoot = new TreeNode(root.val);
        //.val = root.val;
        newRoot.left = cloneTree(root.left);
        newRoot.right = cloneTree(root.right);
        return newRoot;
        
        // Write your code here
    }

    
}