@[zhugechengbin](/user/513194) 题目没有规定 $a$ 数组是不降序，所以，你需要排序。
by lsj2009 @ 2022-05-14 09:37:18
@[zhugechengbin](/user/513194) 先排序再二分
by Mizuki_official @ 2022-05-14 09:41:12
排序呢
by van_Dijk @ 2022-05-14 09:42:26
@[lsj2009](/user/468657) 谢谢
by woshishaobei @ 2022-05-14 09:59:34