bookstore : add to track

config.json

@@ -308,6 +308,11 @@
       "slug": "list-ops",
       "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 +1,62 @@
+import java.util.ArrayList;
+import java.util.stream.Collectors;
+
+public class BookStore{
+	public static double CalculateTotalCost(ArrayList<Integer> books ){
+		return CalculateTotalCost(books,0);
+	}
+
+	public static double CalculateTotalCost (ArrayList<Integer> books,double priceSoFar ){
+		double minPrice = Double.MAX_VALUE;
+
+		if(books.size() == 0)
+			return priceSoFar;
+
+		ArrayList<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 static double CostPerGroup(int groupSize) throws Exception{
+		double discountPercentage;
+		switch (groupSize)
+		{
+		case 1:
+			discountPercentage = 0;
+			break;
+		case 2:
+			discountPercentage = 5;
+			break;
+		case 3:
+			discountPercentage = 10;
+			break;
+		case 4:
+			discountPercentage = 20;
+			break;
+		case 5:
+			discountPercentage = 25;
+			break;
+		default:
+			throw new Exception("Invalide group size : " + groupSize );
+		}
+
+		return 8 * groupSize * (100 - discountPercentage) / 100;
+	}
+
+}

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

@@ -0,0 +1,105 @@
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import org.junit.Test;
+
+public class BookStoreTest{
+
+	@Test
+	public void Basket_with_single_book(){
+		Integer[] p = {1};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(8,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_two_of_same_book(){
+		Integer[] p = {1,1};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(16,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Empty_basket(){
+		ArrayList<Integer> books = new ArrayList<>();
+		assertEquals(0,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_two_different_books(){
+		Integer[] p = {1,2};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+
+		assertEquals(15.20,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_three_different_books(){
+		Integer[] p = {1,2,3};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(21.6,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_four_different_books(){
+		Integer[] p = {1,2,3,4};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(25.6,BookStore.CalculateTotalCost(books),2);
+
+	}
+
+
+	@Test
+	public void Basket_with_five_different_books(){
+		Integer[] p = {1,2,3,4,5};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(30,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_eight_books(){
+		Integer[] p = {1,1,2,2,3,3,4,5};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(51.20,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+
+	@Test
+	public void Basket_with_nine_books(){
+		Integer[] p = {1,1,2,2,3,3,4,4,5};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(55.60,BookStore.CalculateTotalCost(books),2);
+	}
+
+	@Test
+	public void Basket_with_ten_books(){
+		Integer[] p = {1,1,2,2,3,3,4,4,5,5};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(60,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void Basket_with_eleven_books(){
+		Integer[] p = {1,1,2,2,3,3,4,4,5,5,1};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(68,BookStore.CalculateTotalCost(books),2);
+	}
+
+
+	@Test
+	public void  Basket_with_twelve_books(){
+		Integer[] p = {1,1,2,2,3,3,4,4,5,5,1,2};
+		ArrayList<Integer> books = new ArrayList<>(Arrays.asList(p));
+		assertEquals(75.20,BookStore.CalculateTotalCost(books),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'