The British Informatics Olympiad is
the computing competition for schools and colleges.
We are proud to present BIO 2004, sponsored by Lionhead Studios.

BIO2004 Round One question 1 - worked solution

Question 1
Mayan Calendar

The Mayan civilisation used three different calendars. In their long count calendar there were 20 days (called kins) in a uinal, 18 uinals in a tun, 20 tuns in a katun and 20 katuns in a baktun. In our calendar, we specify a date by giving the day, then month, and finally the year. The Maya specified dates in reverse, giving the baktun (1-20), then katun (1-20), then tun (1-20), then uinal (1-18) and finally the kin (1-20).

The Mayan date 13 20 7 16 3 corresponds to the date 1 January 2000 (which was a Saturday).

1 (a)
[24 marks]

Write a program which, given a Mayan date (between 13 20 7 16 3 and 14 1 15 12 3 inclusive), outputs the corresponding date in our calendar. You should output the month as a number.

You are reminded that, in our calendar, the number of days in each month is:

Sample run
13 20 9 2 9
22 3 2001

1	January	31
2	February	28 / 29 (leap year)
3	March	31
4	April	30
5	May	31
6	June	30
7	July	31
8	August	31
9	September	30
10	October	31
11	November	30
12	December	31

	Within the range of dates for this question, every year divisible by 4 is a leap year.
1 (b) [2 marks]	What are the Mayan dates for 1 February 2000 and 1 January 2001?
1 (c) [3 marks]	The Maya believed the universe was destroyed and re-created every cycle of their calendar, which was 20 baktun in length. How many kins (days) are there in a cycle? What day of the week is the last day of the current cycle (20 20 20 18 20)?

Solution program C source code | zip archive with executable and MSVC project
Index of BIO 2004 round one
Index of BIO 2005 sample paper

A worked solution to the problem is in preparation.

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