Zach Marcin 7 лет назад
Родитель
Сommit
844bbe3241

+ 11
- 2
README.md Просмотреть файл

@@ -19,5 +19,14 @@ tests, not the code.
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 6. ArrayListCombiner -- Write two methods, `superCombiner` and `extendCombiner`, which each take two arraylists and append
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 all of the items from the second to the first.  `superCombiner` should use `? super E` and `extendCombiner` should use 
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 `? extends E`.
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-7. MapFunc -- MAke a `map` method that takes an ArrayList and a `Function<T,R>` object and returns an arraylist 
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-containing all of the elements of the first with the function applied to them.
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+7. MapFunc -- Make a `map` method that takes an ArrayList and a `Function<T,R>` object and returns an arraylist 
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+containing all of the elements of the first with the function applied to them.
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+8. Pair -- This is a multi-step one:
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+    1. Create a Pair<E> that stores a pair of elements of type `E`.
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+    2. Create two methods, `min` and `max`, that return the largest and smallest of the `Pair`.
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+    3. Create a utility class called `Arrays` and, in that, create a method
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+    <br>`public static <___> Pair<E> firstLast(ArrayList<___> a)`<br>
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+    That returns a Pair containing the first and last element of the array.  <br>NOTE: The `<___>` is there because you
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+    need to fill in the blank.
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+    4. In `Arrays` make two methods, `min` and `max` that returns the smallest and largest elements in the ArrayList.
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+    5. In `Arrays` make a `minMax` function that returns a `Pair` with the minimum and maximum values of the ArrayList.

+ 16
- 0
src/main/java/Pair/Arrays.java Просмотреть файл

@@ -0,0 +1,16 @@
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+package Pair;
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+
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+import java.util.ArrayList;
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+import java.util.Collections;
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+
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+/**
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+ * In here you must make firstLast, which will return a pair of the first element in the array list and the last
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+ * element in the arraylist.
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+ * You must also make a min method that returns the smallest item in the array list
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+ * A max method that returns the largest item in the arraylist
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+ * And a minmax method that returns a pair containing the largest and smallest items from the array list
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+ */
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+public class Arrays {
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+    public static <___> Pair<E> firstLast(ArrayList<___> a) {
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+    }
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+}

+ 12
- 0
src/main/java/Pair/Pair.java Просмотреть файл

@@ -0,0 +1,12 @@
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+package Pair;
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+
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+/**
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+ * You need to store two values of type `E`, set them in a constructor, and have the following methods,
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+ * getFirst
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+ * getSecond
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+ * min -> returns the minimum of the pair
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+ * max -> returns the maximum of the pair
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+ */
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+public class Pair {
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+
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+}

+ 74
- 0
src/test/java/Pair/ArraysTest.java Просмотреть файл

@@ -0,0 +1,74 @@
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+//package Pair;
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+//
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+//import org.junit.Assert;
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+//import org.junit.Test;
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+//
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+//import java.util.ArrayList;
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+//
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+//public class ArraysTest {
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+//    @Test
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+//    public void firstLast() throws Exception {
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+//        // Given an ArrayList of Integers
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+//        ArrayList<Integer> al = new ArrayList<>();
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+//        al.add(1);
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+//        al.add(5);
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+//        al.add(3);
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+//        al.add(4);
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+//        al.add(2);
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+//        al.add(0);
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+//        al.add(1000);
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+//        // When firstLast is called
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+//        Pair<Integer> result = Arrays.firstLast(al);
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+//        // Then it should return the first and last items
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+//        Assert.assertEquals(new Integer(1), result.getFirst());
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+//        Assert.assertEquals(new Integer(1000), result.getSecond());
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+//    }
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+//
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+//    @Test
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+//    public void testMin() throws Exception {
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+//        // Given an ArrayList of Integers
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+//        ArrayList<Integer> al = new ArrayList<>();
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+//        al.add(1);
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+//        al.add(5);
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+//        al.add(3);
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+//        al.add(4);
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+//        al.add(2);
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+//        al.add(0);
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+//        al.add(1000);
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+//        // When min is called assert that it gets the smallest item
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+//        Assert.assertEquals(new Integer(0), Arrays.min(al));
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+//    }
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+//
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+//    @Test
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+//    public void testMax() throws Exception {
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+//        // Given an ArrayList of Integers
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+//        ArrayList<Integer> al = new ArrayList<>();
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+//        al.add(1);
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+//        al.add(5);
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+//        al.add(3);
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+//        al.add(4);
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+//        al.add(2);
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+//        al.add(0);
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+//        al.add(1000);
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+//        // When min is called assert that it gets the largest item
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+//        Assert.assertEquals(new Integer(1000), Arrays.max(al));
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+//    }
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+//
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+//    @Test
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+//    public void testMinMax() throws Exception {
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+//        // Given an ArrayList of Integers
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+//        ArrayList<Integer> al = new ArrayList<>();
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+//        al.add(1);
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+//        al.add(5);
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+//        al.add(3);
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+//        al.add(4);
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+//        al.add(2);
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+//        al.add(0);
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+//        al.add(1000);
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+//        // When minMax is called
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+//        Pair<Integer> result = Arrays.minMax(al);
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+//        // Then it should return the first and last items
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+//        Assert.assertEquals(new Integer(0), result.min());
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+//        Assert.assertEquals(new Integer(1000), result.max());
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+//    }
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+//}

+ 32
- 0
src/test/java/Pair/PairTest.java Просмотреть файл

@@ -0,0 +1,32 @@
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+//package Pair;
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+//
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+//import org.junit.Test;
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+//import org.junit.Assert;
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+//
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+//public class PairTest {
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+//
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+//    @Test
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+//    public void testGetters() throws Exception {
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+//        // Given a pair with "Foo" and "Bar"
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+//        Pair<String> p = new Pair<String>("Foo", "Bar");
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+//        // When getFirst and getSecond are called, they should be returned.
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+//        Assert.assertEquals("Foo", p.getFirst());
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+//        Assert.assertEquals("Bar",  p.getSecond());
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+//    }
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+//
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+//    @Test
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+//    public void testMin() throws Exception {
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+//        // Given a pair with two values
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+//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
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+//        // When p.min() is called, the smallest should be returned.
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+//        Assert.assertEquals(new Double(1.23), p.min());
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+//    }
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+//
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+//    @Test
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+//    public void testMax() throws Exception {
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+//        // Given a pair with two values
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+//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
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+//        // When p.max() is called, the largest should be returned.
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+//        Assert.assertEquals(new Double(2.34), p.max());
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+//    }
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+//}