C++


(Science: day of the week)

Zeller’s congruence is an algorithm developed by Christian Zeller to calculate the day of the week.

The formula is:

h = (q + 26(m + 1)/10 + k + k/4 + j/4 + 5j) % 7

where

- h is the day of the week (0: Saturday, 1: Sunday, 2: Monday, 3: Tuesday, 4: Wednesday, 5: Thursday, 6: Friday).

- q is the day of the month.

- m is the month (3: March, 4: April, . . . , 12: December). January and February are counted as months 13 and 14 of the previous year.

- j is year/100

- k is the year of the century (i.e., year % 100)

Note that all divisions in this exercise perform an integer division.

Write a program that prompts the user to enter a year, month, and day of the month, and displays the name of the day of the week.

Sample Run 1

Enter year: (e.g., 2012): 2015

Enter month: 1-12: 1

Enter the day of the month: 1-31: 25

Day of the week is Sunday

Sample Run 2

Enter year: (e.g., 2012): 2012

Enter month: 1-12: 5

Enter the day of the month: 1-31: 12

Day of the week is Saturday

(Hint: January and February are counted as 13 and 14 in the formula, so you need to convert the user input 1 to 13 and 2 to 14 for the month and change the year to the previous year.)

For a hint on this program, please see https://liangcpp.pearsoncmg.com/cpprevel2e.html.

If you get a logic or runtime error, please refer to https://liangcpp.pearsoncmg.com/faq.html.