自动生成序号 (10289)

E1 輸入 1

E2=IF(B2="","",IF(B2="一级标题",COUNTIF(B$1:B2,"一级标题"),(ROW()-LOOKUP(1,0/(B$1:B1="一级标题"),ROW($1:1)))/10+LOOKUP(1,0/(B$1:B1="一级标题"),E$1:E1)))