Long year: Difference between revisions

=={{header|jq}}==

{{works with|jq}}

'''Works with gojq, the Go implementation of jq'''

Using Zeller's congruence ...<lang jq>

# Use Zeller's Congruence to determine the day of the week, given

# year, month and day as integers in the conventional way.

# Emit 0 for Saturday, 1 for Sunday, etc.

#

def day_of_week($year; $month; $day):

if $month == 1 or $month == 2 then

[$month + 12, $year - 1]

else

[$month, $year]

end

| $day + (13*(.[0] + 1)/5|floor)

+ (.[1]%100) + ((.[1]%100)/4|floor)

+ (.[1]/400|floor) - 2*(.[1]/100|floor)

| . % 7 ;

def has53weeks:

day_of_week(.; 1; 1) == 5 or day_of_week(.; 12; 31) == 5;

# To display results neatly:

def nwise($n):

def n: if length <= $n then . else .[0:$n] , (.[$n:] | n) end;

n;

"Long years from 1900 to 2100 inclusive:",

([range(1900;2101) | select(has53weeks)] | nwise(10) | join(", "))</lang>

{{out}}

<pre>

Long years in 1900-2100 inclusive:

1903, 1908, 1914, 1920, 1925, 1931, 1936, 1942, 1948, 1953

1959, 1964, 1970, 1976, 1981, 1987, 1992, 1998, 2004, 2009

2015, 2020, 2026, 2032, 2037, 2043, 2048, 2054, 2060, 2065

2071, 2076, 2082, 2088, 2093, 2099

</pre>