排序排两次就行，没必要循环排 亲测ac [code](https://www.luogu.org/paste/usfgwv87) by WSEDSWZD @ 2018-06-01 11:06:46
哎呀，低级错误啊。谢谢！ by hanrui_l @ 2018-06-01 11:11:02