租借天数 (10862)

J2=IF(C2="租借",,A2-IFERROR(LOOKUP(1,0/(B$1:B1=B2)/(C$1:C1="租借"),A$1:A1),A2))

另解=A2-LOOKUP(1,0/(B$2:B2=B2)/(C$2:C2="租借"),A$2:A2)