57 lines
1.5 KiB
C#
57 lines
1.5 KiB
C#
using System;
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class Doom {
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public static void Main(string[] args) {
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Date[] dates = {
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new Date(1800,1,6),
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new Date(1875,3,29),
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new Date(1915,12,7),
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new Date(1970,12,23),
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new Date(2043,5,14),
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new Date(2077,2,12),
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new Date(2101,4,2)
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};
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foreach (Date d in dates)
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Console.WriteLine($"{d.Format()}: {d.Weekday()}");
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}
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}
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class Date {
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private int year, month, day;
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private static readonly int[] leapDoom = {4,1,7,4,2,6,4,1,5,3,7,5};
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private static readonly int[] normDoom = {3,7,7,4,2,6,4,1,5,3,7,5};
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public static readonly string[] weekdays = {
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"Sunday", "Monday", "Tuesday", "Wednesday",
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"Thursday", "Friday", "Saturday"
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};
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public Date(int year, int month, int day) {
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this.year = year;
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this.month = month;
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this.day = day;
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}
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public bool IsLeapYear() {
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return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
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}
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public string Format() {
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return $"{month:00}/{day:00}/{year:0000}";
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}
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public string Weekday() {
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int c = year / 100;
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int r = year % 100;
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int s = r / 12;
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int t = r % 12;
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int cAnchor = (5 * (c % 4) + 2) % 7;
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int doom = (s + t + t / 4 + cAnchor) % 7;
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int anchor =
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IsLeapYear() ? leapDoom[month - 1] : normDoom[month - 1];
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return weekdays[(doom + day - anchor + 7) % 7];
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}
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}
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