rman_to_decimal.f95

!THIS PROGRAM FINDING THE DECIMAL EQUIVALENT OF A ROMAN NUMBER
!I=1,II=2,III=3,IV=4,V=5,VI=6,VII=7,VIII=8,IX=9,X=10,XL=40,L=50,XC=90,C=100
!CM=900,M=1000,V_BAR=5000,X_BAR=10000,C_BAR=100000,M_BAR=1000000;;XLIV==44;LXXXII=82

PROGRAM ROM_TO_DEC
 IMPLICIT NONE
 INTEGER::DEC=0,I,J,L,DIG(1:10),BIG_DIG=0,BIG_POS
 CHARACTER(LEN=10)::ROM,ROM_DIG
 INTEGER::ROMAN_DIGIT
!INITIALISE ALL DIGIT TO ZERO
DO I=1,10
 DIG(I)=0
END DO
PRINT *,"ENTER A ROMAN NUMBER"
READ 10,ROM
10 FORMAT(A10)
ROM=TRIM(ROM)
L=LEN_TRIM(ROM)!this is trimming for any space
!NOW FINDOUT THE DIGIT OF ROMAN NUMBER
DO I=1,L
ROM_DIG=ROM(I:I)
DIG(I)=ROMAN_DIGIT(ROM_DIG)
IF(DIG(I)>BIG_DIG)THEN
 BIG_DIG=DIG(I)
 BIG_POS=I
ENDIF
END DO

DO I=1,L
IF(I<BIG_POS)THEN
DEC=DEC-DIG(I)
ELSE
DEC=DEC+DIG(I)
ENDIF
END DO

PRINT 100,DEC
100 FORMAT(2X,"DECIMAL EQUIVALENT NUMBER IS:",I4)
END PROGRAM ROM_TO_DEC






INTEGER FUNCTION ROMAN_DIGIT(N)
 IMPLICIT NONE
 CHARACTER(LEN=1),INTENT(IN)::N
! SELECT CASE(N)
 ! CASE("I")
  ! ROMAN_DIGIT=1
!  CASE("V")
!   ROMAN_DIGIT=5
!  CASE("X")
 !  ROMAN_DIGIT=10
!  CASE("L")
!   ROMAN_DIGIT=50
!  CASE("C")                     !this function finding each digit of roman number into decimal equivalent number
!   ROMAN_DIGIT=100
!  CASE("M")
!   ROMAN_DIGIT=1000
! END SELECT

IF(N=="I" .OR. N=="i")THEN
ROMAN_DIGIT=1
ELSEIF(N=="V" .OR. N=="v")THEN
ROMAN_DIGIT=5
ELSEIF(N=="X" .OR. N=="x")THEN
ROMAN_DIGIT=10
ELSEIF(N=="L" .OR. N=="l")THEN
ROMAN_DIGIT=50
ELSEIF(N=="C" .OR. N=="c")THEN
ROMAN_DIGIT=100
ELSEIF(N=="M" .OR. N=="m")THEN
ROMAN_DIGIT=1000
ENDIF
END FUNCTION ROMAN_DIGIT