输出保留 12 位小数的浮点数

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	杨家齐xly2025	32ms	728 KiB	C++14(O2)	135 Bytes	2025-8-7 19:39:29
AC	maochengjun	34ms	808 KiB	C++14	143 Bytes	2025-7-9 11:38:25
AC	张芷若xly2025	34ms	744 KiB	C++14(O2)	145 Bytes	2025-8-7 20:08:12
AC	龙肖瑾xly2025	34ms	728 KiB	C++14(O2)	143 Bytes	2025-7-27 22:03:47
AC	若白	35ms	816 KiB	C++17(O2)	124 Bytes	2025-7-11 14:38:46
AC	女乃龙	35ms	824 KiB	C++14(O2)	143 Bytes	2025-7-11 14:41:55
AC	陈国瑞	36ms	808 KiB	C++14(O2)	157 Bytes	2025-7-15 17:18:47
AC	_chjich_	39ms	732 KiB	C++14(O2)	124 Bytes	2025-7-11 9:31:56
AC	曾彦彬contest	39ms	804 KiB	C++14(O2)	167 Bytes	2025-7-7 19:41:37
AC	xzh13579	39ms	808 KiB	C++14(O2, GCC 9.3.0)	184 Bytes	2025-7-24 23:23:41