lots of exercises in java... from https://github.com/exercism/java

Harikrushna Vanpariya 4759dd9be1 forth: update version file (1.4.0 -> 1.5.0) #1377 change: update version file (1.1.0 -> 1.2.0) #1376 list-ops: update version file (2.0.0 -> 2.2.0) #1375 book-store: update version file (1.2.0 -> 1.3.0) #1373 circular-buffer: update version file (1.0.1 -> 1.1.0) #1371 ocr-numbers: update version file (1.0.0 -> 1.1.0) #1370 wordy: update version file (1.0.0 -> 1.1.0) #1362 minesweeper: update version file (1.0.0 -> 1.1.0) #1361		6 年之前
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.meta	forth: update version file (1.4.0 -> 1.5.0) #1377 change: update version file (1.1.0 -> 1.2.0) #1376 list-ops: update version file (2.0.0 -> 2.2.0) #1375 book-store: update version file (1.2.0 -> 1.3.0) #1373 circular-buffer: update version file (1.0.1 -> 1.1.0) #1371 ocr-numbers: update version file (1.0.0 -> 1.1.0) #1370 wordy: update version file (1.0.0 -> 1.1.0) #1362 minesweeper: update version file (1.0.0 -> 1.1.0) #1361	6 年之前
src	book-store: update test suite to 1.2.0	6 年之前
README.md	Adjust exercise README formatting; drop help link	7 年之前
build.gradle	Format build.gradle files	7 年之前

Book Store

To try and encourage more sales of different books from a popular 5 book series, a bookshop has decided to offer discounts on multiple book purchases.

One copy of any of the five books costs $8.

If, however, you buy two different books, you get a 5% discount on those two books.

If you buy 3 different books, you get a 10% discount.

If you buy 4 different books, you get a 20% discount.

If you buy all 5, you get a 25% discount.

Note: that if you buy four books, of which 3 are different titles, you get a 10% discount on the 3 that form part of a set, but the fourth book still costs $8.

Your mission is to write a piece of code to calculate the price of any conceivable shopping basket (containing only books of the same series), giving as big a discount as possible.

For example, how much does this basket of books cost?

2 copies of the first book
2 copies of the second book
2 copies of the third book
1 copy of the fourth book
1 copy of the fifth book

One way of grouping these 8 books is:

1 group of 5 --> 25% discount (1st,2nd,3rd,4th,5th)
+1 group of 3 --> 10% discount (1st,2nd,3rd)

This would give a total of:

5 books at a 25% discount
+3 books at a 10% discount

Resulting in:

5 x (8 - 2.00) == 5 x 6.00 == $30.00
+3 x (8 - 0.80) == 3 x 7.20 == $21.60

For a total of $51.60

However, a different way to group these 8 books is:

1 group of 4 books --> 20% discount (1st,2nd,3rd,4th)
+1 group of 4 books --> 20% discount (1st,2nd,3rd,5th)

This would give a total of:

4 books at a 20% discount
+4 books at a 20% discount

Resulting in:

4 x (8 - 1.60) == 4 x 6.40 == $25.60
+4 x (8 - 1.60) == 4 x 6.40 == $25.60

For a total of $51.20

And $51.20 is the price with the biggest discount.

Running the tests

You can run all the tests for an exercise by entering

$ gradle test

in your terminal.

Source

Inspired by the harry potter kata from Cyber-Dojo. http://cyber-dojo.org

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

README.md

Book Store

Running the tests

Source

Submitting Incomplete Solutions