Easter Calculation

Our current calendar system is based upon the Gregorian calendar, which took effect in 1583.

Calculating the date of Easter each year is a difficult exercise. In 1876, the following algorithm for calculating the date of Easter was proposed. Samuel Butcher, the Bishop of Meade, later demonstrated that this algorithm is accurate.

a = year % 19

b = year / 100

c = year % 100

d = b / 4

e = b % 4

f = (b + 8) / 25

g = (b - f + 1) / 3

h = ((19 * a) + b - d - g + 15) % 30

i = c / 4

j = c % 4

k = (32 + (2 * e) + (2 * i) - h - j) % 7

m = (a + (11 * h) + (22 * k) ) / 451

Easter Month = ( h + k - (7 * m) + 114 ) / 31 // where 3 means the month of March and 4 means April

p = ( h + k - (7 * m) + 114 ) % 31 Easter Date = p + 1 In the above calculations, "/" is the integer-division operator, which returns the integer result of the division operation (quotient); "%" is the modulus operator, which returns the integer remainder. Both operands passed to the integer-division and the modulus operators must be integers.

Here's an example:

9 \ 5 = 1

9 % 5 = 4

The order of operations (or operator precedence) is a set of rules defining which operations to perform first when evaluating a given mathematical expression. For example, the rules of operator precedence dictate that the multiplication operator ("*") is evaluated before the addition operator ("+"). Parentheses inserted into an expression can override the natural order of precedence.

Write a C++ program that prompts for the year and then calculates the date of Easter. A sample program dialog is shown below.

What's the year: 2006 Easter Month is April Easter Day is 16 What's the year: 2005 Easter Month is March Easter Day is 27

What's the year: 2004 Easter Month is April Easter Day is 11 HINT: You might try building these calculations inside MS Excel and then do them step-by-step verifying the values calculated in your program against your spreadsheet answers.