牛客網編程-求樹的鏡像（java）

思路：遞歸將樹的左右節點交換

代碼：

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

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

    }

}
*/
public class Solution {
    public void Mirror(TreeNode root) {
    	mirror(root);
    }
    static void mirror(TreeNode root){
        if(root == null){
        	return;    
        }
        
        TreeNode temp = root.right;
        root.right = root.left;
        root.left = temp;
        mirror(root.right);
        mirror(root.left);
    }
}

end