Update calculator.c
Update calculator.c
IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest,IEEE-NITK/HacktoberFest