Number of Days in a Month

🏠 ⬅️ ➡️

Given a year year and a month month, return the number of days of that month.

Example 1:

Input: year = 1992, month = 7 Output: 31

Example 2:

Input: year = 2000, month = 2 Output: 29

Example 3:

Input: year = 1900, month = 2 Output: 28

Constraints:

  • 1583 <= year <= 2100
  • 1 <= month <= 12
Note: This problem is from LeetCode.
✅ Compiled
✅ Executed
⚠️ Correct 
program main
    implicit none

    integer :: year, month, days

    ! Example 1
    year = 1992
    month = 7
    days = get_days(year, month)
    print '(A, I0, A, I0, A, I0)', 'Year ', year, ' Month ', month, &
        ' has ', days, ' days.'

    ! Example 2
    year = 2000
    month = 2
    days = get_days(year, month)
    print '(A, I0, A, I0, A, I0)', 'Year ', year, ' Month ', month, &
        ' has ', days, ' days.'

    ! Example 3
    year = 1900
    month = 2
    days = get_days(year, month)
    print '(A, I0, A, I0, A, I0)', 'Year ', year, ' Month ', month, &
        ' has ', days, ' days.'

contains

    function get_days(year, month) result(days)
        implicit none
        integer, intent(in) :: year, month
        integer :: days

        select case (month)
            case (1, 3, 5, 7, 8, 10, 12)
                days = 31
            case (4, 6, 9, 11)
                days = 30
            case (2)
                if (mod(year, 4) == 0) then
                    days = 29
                else
                    days = 28
                end if
        end select
    end function get_days
end program main
✅ Compiled
✅ Executed
❌ Correct 
! This is a full Fortran script with a valid main entry point that solves the problem
! of finding the number of days in a given month.

! Input:
!   year: the year
!   month: the month
! Output:
!   the number of days in the month

integer, parameter :: year = 1992
integer, parameter :: month = 7

integer :: days

! Check if the year is a leap year
if (mod(year, 4) == 0) then
    ! If the year is a leap year, check if the month is February
    if (month == 2) then
        ! If the month is February, return 29
        days = 29
    else
        ! If the month is not February, return 31
        days = 31
    end if
else
    ! If the year is not a leap year, return 31
    days = 31
end if

! Print the number of days in the month
write (*, '(A, I0, A, I0, A)') 'The number of days in month ', month, ' of year ', year, ' is ', days

end program
🌐 Data from online sources 
def number_of_days(year, month):
    if month == 2:
        if (year % 4 == 0 and year % 100 != 0) or year % 400 == 0:
            return 29
        return 28
    if month in [4, 6, 9, 11]:
        return 30
    return 31

The algorithm first checks if the given month is February. If it is, then it determines if the given year is a leap year. A leap year is a year that is divisible by 4 and not divisible by 100, or divisible by 400. If it is a leap year, it returns 29 as the number of days in February; otherwise, it returns 28.

If the given month is April, June, September, or November, the algorithm returns 30 as the number of days in that month. For all other months (January, March, May, July, August, October, and December), the algorithm returns 31 as the number of days in that month.

🌐 Data from online sources 
int numberOfDays(int year, int month) {
    if(month == 2) {
        if((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
            return 29;
        return 28;
    }
    if(month == 4 || month == 6 || month == 9 || month == 11)
        return 30;
    return 31;
}

The algorithm first checks if the given month is February. If it is, then it determines if the given year is a leap year. A leap year is a year that is divisible by 4 and not divisible by 100, or divisible by 400. If it is a leap year, it returns 29 as the number of days in February; otherwise, it returns 28.

If the given month is April, June, September, or November, the algorithm returns 30 as the number of days in that month. For all other months (January, March, May, July, August, October, and December), the algorithm returns 31 as the number of days in that month.