求三个数的平均数

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	liuhaoqi	6ms	9 MiB	C++98	154 Bytes	2024-10-20 11:37:31
AC	jiangxingxing	6ms	9 MiB	C++98	179 Bytes	2024-12-14 14:33:38
AC	baoyufu	6ms	9 MiB	C++98	177 Bytes	2024-10-25 19:44:15
AC	wangyuxiang	7ms	9 MiB	C++98	168 Bytes	2024-10-5 11:43:12
AC	jianghaoyan	7ms	9 MiB	C++98	171 Bytes	2024-10-20 11:50:33
AC	heliangyu	7ms	9 MiB	C++98	176 Bytes	2024-8-29 9:59:29
AC	huangshengfeng	16ms	9 MiB	C++98	164 Bytes	2025-4-3 17:57:39