bookstore : add to track

config.json

@@ -315,10 +315,15 @@
       "difficulty": 1,
       "topics": []
     },
-    {
+     {
       "slug": "isogram",
       "difficulty": 1,
       "topics": []
+    },
+    {
+      "slug": "book-store",
+      "difficulty": 1,
+      "topics": []
     }
   ],
   "deprecated": [

exercises/book-store/build.gradle

@@ -0,0 +1,17 @@
+apply plugin: "java"
+apply plugin: "eclipse"
+apply plugin: "idea"
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  testCompile "junit:junit:4.12"
+}
+test {
+  testLogging {
+    exceptionFormat = 'full'
+    events = ["passed", "failed", "skipped"]
+  }
+}

exercises/book-store/src/example/java/Bookstore.java

@@ -0,0 +1,61 @@
+import java.awt.print.Printable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Bookstore{
+
+	private static int BOOK_PRICE = 8, MAX_GROUP_SIZE = 5;
+	private List<Integer> books;
+	private static double[] DISCOUNT_TIERS = {0,5,10,20,25};   	
+
+	public Bookstore (List<Integer> books){
+		this.books = books;
+	}	
+
+
+
+
+	public double calculateTotalCost(){
+		return calculateTotalCost(this.books,0);
+	}
+
+	private double calculateTotalCost (List<Integer> books,double priceSoFar ){
+		double minPrice = Double.MAX_VALUE;
+
+
+		if(books.size() == 0){
+			return priceSoFar;
+		}
+
+		List<Integer> groups = (ArrayList<Integer>) books.stream().distinct().collect(Collectors.toList());
+
+
+		double price = 0;
+
+		for(int i = 0;i<groups.size();i++){
+			books.remove(groups.get(i));	
+		}
+
+		try {
+			price = calculateTotalCost(books,priceSoFar + costPerGroup(groups.size()));
+		} catch (Exception e) {
+			e.printStackTrace();
+		}
+
+		minPrice = Math.min(minPrice, price);
+		return minPrice;
+
+
+	}
+
+	private double costPerGroup(int groupSize) throws Exception{
+		if (groupSize < 1 || groupSize > MAX_GROUP_SIZE){
+        		throw new Exception("Invalid group size : " + groupSize );
+     		}
+    		return BOOK_PRICE * groupSize * (100 - DISCOUNT_TIERS[groupSize-1])/100;
+	}
+
+
+}

exercises/book-store/src/test/java/BookstoreTest.java

@@ -0,0 +1,117 @@
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.junit.Test;
+
+public class BookstoreTest{
+
+	@Test
+	public void onlyASingleBook(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(8,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void twoOfSameBook(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(16,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void emptyBasket(){
+		List<Integer> books = new ArrayList<>();
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(0,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void twoDifferentBooks(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,2));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(15.20,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void threeDifferentBooks(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,2,3));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(21.6,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void fourDifferentBooks(){
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(1,2,3,4));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(25.6,bookstore.calculateTotalCost(),2);
+
+	}
+
+	@Ignore
+	@Test
+	public void fiveDifferentBooks(){
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(1,2,3,4,5));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(30,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void twoGroupsOfFourIsCheaperThanGroupOfFivePlusGroupOfThree(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,3,4,5));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(51.20,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void groupOfFourPlusGroupOfTwoIsCheaperThanTwoGroupsOfThree(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,4));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(40.8,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void twoEachOfFirst4BooksAnd1CopyEachOfRest(){
+		Integer[] p = {1,1,2,2,3,3,4,4,5};
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,3,4,4,5));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(55.60,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void twoCopiesOfEachBook(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,3,4,4,5,5));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(60.00,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void threeCopiesOfFirstBookAnd2EachOfRemaining(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,3,4,4,5,5,1));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(68.00,bookstore.calculateTotalCost(),2);
+	}
+
+	@Ignore
+	@Test
+	public void threeEachOFirst2BooksAnd2EachOfRemainingBooks(){
+		List<Integer> books = new ArrayList<>(Arrays.asList(1,1,2,2,3,3,4,4,5,5,1,2));
+		Bookstore bookstore = new Bookstore(books);
+		assertEquals(75.20,bookstore.calculateTotalCost(),2);
+	}
+
+}
+

exercises/settings.gradle

@@ -9,6 +9,7 @@ include 'binary'
 include 'binary-search'
 include 'binary-search-tree'
 include 'bob'
+include 'book-store'
 include 'bracket-push'
 include 'change'
 include 'clock'