focal loss计算

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	B1aoT50mjG	1895ms	35.6 MiB	Python 3	587 Bytes	2026-9-12 16:46:50
AC	安静的浪花9322	1902ms	35.5 MiB	Python 3	554 Bytes	2026-9-18 18:38:09
AC	风趣的金鱼6934	1934ms	35.6 MiB	Python 3	541 Bytes	2026-10-13 20:58:14
AC	进取的红叶7686	1944ms	35.4 MiB	Python 3	537 Bytes	2026-10-9 15:50:51
AC	睿智的山泉6678	2033ms	35.5 MiB	Python 3	642 Bytes	2026-10-13 14:47:49
AC	爱笑的小鹿9928	2070ms	35.5 MiB	Python 3	513 Bytes	2026-10-5 20:42:07
AC	诚恳的青竹5863	2302ms	35.3 MiB	Python 3	617 Bytes	2026-10-15 21:14:42