大小写字母转化

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	Iris39	14ms	540 KiB	C++17	365 Bytes	2025-6-7 18:19:39
AC	Ken	14ms	760 KiB	C++14(O2)	454 Bytes	2025-6-7 12:32:14
AC	20210614	15ms	616 KiB	C++14(O2)	300 Bytes	2025-6-9 22:35:22
AC	20210137	15ms	588 KiB	C++14(O2)	280 Bytes	2025-6-7 20:11:41
AC	lucas	15ms	548 KiB	C++20(O2)	320 Bytes	2025-6-9 23:12:38
AC	wujunxi	15ms	604 KiB	C++14(O2)	296 Bytes	2025-6-8 22:31:29