最后同數字的位置标记为1(9423)

C2=IF((COUNTIF(B:B,E$2)=COUNTIF(B$2:B2,B2))*(B2=E$2),1,"")

C2{=REPT(1,LOOKUP(1,0/(B$2:B999=E$2),ROW($2:999))=ROW())