Leap year

Algorithm
Step 1 : Start
Step 2 : Read the value of year
Step 3 : If year divisible by 400 then
Print "Leap year"
Step 3.1 : else if year divisible by 4 and not divisible by 100 then
Print "Leap year"
Step 3.2 : else
Print "Not a leap year"
Step 4 : Stop

Program (leap.sh)
# Leap year
echo -n "Enter a year : "
read year
rem1=`expr $year % 4`
rem2=`expr $year % 100`
rem3=`expr $year % 400`
if [ $rem3 -eq 0 ]
then
echo "$year is a Leap Year"
elif [ $rem2 -ne 0 -a $rem1 -eq 0 ]

then
echo "$year is a Leap Year"
else
echo "$year is Not a leap year"
fi

Output
[vijai@localhost decision]$ sh leap.sh
Enter a year : 1900
1900 is Not a leap year