隨機不重複完全取值 且數據可增減 (13509)

C2下拉 {=IF(B2="","",OFFSET(B$1,SMALL(IF((COUNTIF(C$1:C1,B$2:B$299)=0)*(B$2:B$299<>""),ROW($1:$298)),RANDBETWEEN(1,COUNTA(B:B)-ROW(A1))),))

E2{=AND(COUNTIF(C:C,OFFSET(B2,,,COUNTA(B:B)-1))=1)