Self-hatred

Project Euler Problem #19

Mark now knows more than Mark ever wished to know about leap years, months, days, and weeks – generally a whole lot of the Georgian calendar and calendar days versus solar days.

using System;

public class Nineteen
{
	static void Main()
	{	
		int a = 0;

		for (int i = 1901; i < = 2000; i++)
			for (int j = 1; j <= 12; j++)
				 if (Dow(i,j,1) == 0)
				 	a++;

		Console.WriteLine("\n{0}\n", a);
	}

	static int Dow(int year, int month, int day)
	{
		int a = 1900;
		int b = 1;
		int c = 1;
		int d = Elapsed(a,b,c,year,month,day);

		return d %= 7;
	}

	// Days between any two arbitrary dates. Inclusive!
	static int Elapsed(int yOne, int mOne, int dOne, int yTwo, int mTwo, int dTwo)
	{
		int a = 0;

		for (int i = yOne; i < yTwo; i++)
			a += DaysYear(i);
		for (int i = mOne; i < mTwo; i++)
			a += DaysMonth(yTwo, i);
		if (dTwo >= dOne)
			a += dTwo;
		else 
			a += dOne;

		return a;
	}

	// Days in one month. Assumes "1-12" input. Adjusts for leap year.
	static int DaysMonth(int year, int month)
	{
		int[]  a = new int[13] {-42,31,28,31,30,31,30,31,31,30,31,30,31};
		int	 b = 0;

		b = a[month];

		if ((Leap(year)) && (month == 2))
			b += 1;

		return b;
	}

	// Days in one year period.
	static int DaysYear(int year)
	{
		int a = 0;

		for (int i = 1; i < = 12; i++)
			a += DaysMonth(year, i);

		return a;
	}

	static bool Leap(int year)
	{
		bool a = false;

		if (year % 400 == 0)
			a = true;
		else if (year % 100 == 0)
			a = false;
		else if (year % 4 == 0)
			a = true;
		else
			a = false;

		return a;
	}
}

Tagged with: 19, c, calendar, csharp, date, georgian, nineteen, problem, project euler, projecteuler, solution

Categorised as: programming