Accurately the Earth has 365.24 days per year, to correct the approximation and keep track of the Solar Calendar the idea of leap year has been introduced to Gregorian Calendar. A leap year comes once every four years. In contrast, it has 366 days with regular years, having 365 days.
Mathematical approach to check:
- Every year is a Leap year if it is evenly divided by four.
- Every year evenly divided by 100 BUT not 400 is not a leap year.
- Every year evenly divided by 400 is a leap year.
Use the following shell script for the same.
echo -n "Enter year (YYYY): "
read y
a = 'expr $y%4'
b = 'expr $y%100'
c = 'expr $y%400'
if [$a -eq 0 -a $b -ne 0 -o $c -eq 0]
then
echo "$y is leap year"
else
echo "$y is not a leap year"
fi
Example:
Input: 2024
Output: "2024 is leap year"
Time complexity: O(1) because it is doing constant operations
Auxiliary space: O(1)