输出保留 3 位小数的浮点数

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	严晨航	31ms	808 KiB	C++14(O2)	142 Bytes	2025-8-26 15:55:40
AC	Harry	32ms	812 KiB	C++14	175 Bytes	2025-8-18 18:50:05
AC	sage2012	33ms	808 KiB	C++14(O2)	126 Bytes	2025-9-19 20:46:07
AC	张叶朵	33ms	804 KiB	C++14(O2)	160 Bytes	2025-8-27 23:10:48
AC	w20120404	34ms	852 KiB	C++14(O2)	138 Bytes	2025-8-19 15:14:18
AC	龙肖瑾xly2025	34ms	768 KiB	C++14(O2)	142 Bytes	2025-7-27 22:03:20
AC	谭博文	34ms	808 KiB	C++14(O2)	135 Bytes	2025-10-7 14:19:01
AC	若白	35ms	764 KiB	C++17(O2)	122 Bytes	2025-7-11 14:37:50
AC	maochengjun	35ms	808 KiB	C++14	141 Bytes	2025-7-9 11:38:05
AC	刘熠辰	35ms	808 KiB	C++14(O2)	136 Bytes	2025-9-18 15:36:12
AC	陈国瑞	36ms	804 KiB	C++14(O2)	150 Bytes	2025-7-15 17:17:29
AC	xzh13579	36ms	808 KiB	C++14(O2)	188 Bytes	2025-7-24 23:22:09
AC	张芷若xly2025	36ms	908 KiB	C++14(O2)	144 Bytes	2025-8-8 8:33:57
AC	卢皓禹xly2025	36ms	808 KiB	C++14(O2)	143 Bytes	2025-8-31 21:28:39
AC	lyd	37ms	748 KiB	C++14(O2)	132 Bytes	2025-9-25 17:11:28
AC	_chjich_	38ms	808 KiB	C++14(O2)	122 Bytes	2025-7-11 9:31:38
AC	曾彦彬contest	38ms	812 KiB	C++14(O2)	166 Bytes	2025-7-7 19:41:20
AC	张隽语xly2025	38ms	808 KiB	C++14(O2)	142 Bytes	2025-9-6 16:10:41
AC	王思懿	38ms	808 KiB	C++14(O2)	144 Bytes	2025-8-18 10:52:16
AC	女乃龙	38ms	868 KiB	C++14(O2)	141 Bytes	2025-7-11 14:41:35
AC	Mch121018	39ms	808 KiB	C++17(O2)	136 Bytes	2025-9-4 22:48:43