local VALUES=( 1000 900 500 400 100 90 50 40 10 5 4 1 )

# 1990 is rendered as MCMXC (1000 = M, 900 = CM, 90 = XC)

local R_VALUES=(

[1000]=M [900]=CM [500]=D [400]=CD

[100]=C [90]=XC [50]=L [40]=XL

[10]=X [9]=IX [5]=V [4]=IV

[1]=I

)

local INUM=""

local NUM=$1

# loop from Array VALUES 1000 to 1

for VAL in ${VALUES[@]}; do

while (( NUM >= VAL )); do

INUM+=${R_VALUES[VAL]}

((NUM -= VAL))

done

done

echo $INUM

local ROMAN=$1

local INUM=0

local PREV=0

for ((i=${#ROMAN}-1;i>=0;i--));do

case "${ROMAN:$i:1}" in

M) VAL=1000 ;;

D) VAL=500 ;;

C) VAL=100 ;;

L) VAL=50 ;;

X) VAL=10 ;;

V) VAL=5 ;;

I) VAL=1 ;;

esac

if [[ $VAL -lt $PREV ]]

then

let INUM-=VAL

else

let INUM+=VAL

fi

PREV=$VAL

done

echo "$INUM"