Eric Cordell 6 years ago
parent
commit
6bb1307d3b

+ 33
- 4
src/main/java/Pair/Arrays.java View File

@@ -10,7 +10,36 @@ import java.util.Collections;
10 10
  * A max method that returns the largest item in the arraylist
11 11
  * And a minmax method that returns a pair containing the largest and smallest items from the array list
12 12
  */
13
-//public class Arrays {
14
-//    public static <___> Pair<E> firstLast(ArrayList<___> a) {
15
-//    }
16
-//}
13
+public class Arrays {
14
+
15
+    public static <E extends Comparable> Pair<E> firstLast(ArrayList<E> a) {
16
+        return new Pair(a.get(0), a.get(a.size() - 1));
17
+    }
18
+
19
+
20
+    public static <E extends Comparable> Comparable min(ArrayList<E> al) {
21
+        return Collections.min(al);
22
+    }
23
+
24
+
25
+    public static <E extends Comparable> Comparable max(ArrayList<E> al) {
26
+        return Collections.max(al);
27
+    }
28
+
29
+    public static <E extends Comparable> Pair minMax(ArrayList<E> al) {
30
+        return new Pair<>(min(al), max(al));
31
+    }
32
+
33
+}
34
+
35
+
36
+
37
+//Pair -- This is a multi-step one:
38
+//        Create a Pair that stores a pair of elements of type E.
39
+//        Create two methods, min and max, that return the largest and smallest of the Pair.
40
+//        Create a utility class called Arrays and, in that, create a method
41
+//        public static <___> Pair<E> firstLast(ArrayList<___> a)
42
+//        That returns a Pair containing the first and last element of the array.
43
+//        NOTE: The <___> is there because you need to fill in the blank.
44
+//        In Arrays make two methods, min and max that returns the smallest and largest elements in the ArrayList.
45
+//        In Arrays make a minMax function that returns a Pair with the minimum and maximum values of the ArrayList.

+ 34
- 1
src/main/java/Pair/Pair.java View File

@@ -1,5 +1,7 @@
1 1
 package Pair;
2 2
 
3
+import java.util.Collections;
4
+
3 5
 /**
4 6
  * You need to store two values of type `E`, set them in a constructor, and have the following methods,
5 7
  * getFirst
@@ -7,6 +9,37 @@ package Pair;
7 9
  * min -> returns the minimum of the pair
8 10
  * max -> returns the maximum of the pair
9 11
  */
10
-public class Pair {
12
+public class Pair<E extends Comparable> {
13
+
14
+    private E first;
15
+    private E second;
16
+
17
+    public E getFirst() {
18
+        return first;
19
+    }
20
+
21
+    public E getSecond() {
22
+        return second;
23
+    }
24
+
25
+    public Pair(E first, E second) {
26
+        this.first = first;
27
+        this.second = second;
28
+    }
29
+
30
+
31
+    public E min() {
32
+        if( first.compareTo(second) < 0){
33
+            return first;
34
+        }
35
+        return second;
36
+    }
37
+
38
+    public E max() {
39
+        if( first.compareTo(second) > 0){
40
+            return first;
41
+        }
42
+        return second;
43
+    }
11 44
 
12 45
 }

+ 74
- 74
src/test/java/Pair/ArraysTest.java View File

@@ -1,74 +1,74 @@
1
-//package Pair;
2
-//
3
-//import org.junit.Assert;
4
-//import org.junit.Test;
5
-//
6
-//import java.util.ArrayList;
7
-//
8
-//public class ArraysTest {
9
-//    @Test
10
-//    public void firstLast() throws Exception {
11
-//        // Given an ArrayList of Integers
12
-//        ArrayList<Integer> al = new ArrayList<>();
13
-//        al.add(1);
14
-//        al.add(5);
15
-//        al.add(3);
16
-//        al.add(4);
17
-//        al.add(2);
18
-//        al.add(0);
19
-//        al.add(1000);
20
-//        // When firstLast is called
21
-//        Pair<Integer> result = Arrays.firstLast(al);
22
-//        // Then it should return the first and last items
23
-//        Assert.assertEquals(new Integer(1), result.getFirst());
24
-//        Assert.assertEquals(new Integer(1000), result.getSecond());
25
-//    }
26
-//
27
-//    @Test
28
-//    public void testMin() throws Exception {
29
-//        // Given an ArrayList of Integers
30
-//        ArrayList<Integer> al = new ArrayList<>();
31
-//        al.add(1);
32
-//        al.add(5);
33
-//        al.add(3);
34
-//        al.add(4);
35
-//        al.add(2);
36
-//        al.add(0);
37
-//        al.add(1000);
38
-//        // When min is called assert that it gets the smallest item
39
-//        Assert.assertEquals(new Integer(0), Arrays.min(al));
40
-//    }
41
-//
42
-//    @Test
43
-//    public void testMax() throws Exception {
44
-//        // Given an ArrayList of Integers
45
-//        ArrayList<Integer> al = new ArrayList<>();
46
-//        al.add(1);
47
-//        al.add(5);
48
-//        al.add(3);
49
-//        al.add(4);
50
-//        al.add(2);
51
-//        al.add(0);
52
-//        al.add(1000);
53
-//        // When min is called assert that it gets the largest item
54
-//        Assert.assertEquals(new Integer(1000), Arrays.max(al));
55
-//    }
56
-//
57
-//    @Test
58
-//    public void testMinMax() throws Exception {
59
-//        // Given an ArrayList of Integers
60
-//        ArrayList<Integer> al = new ArrayList<>();
61
-//        al.add(1);
62
-//        al.add(5);
63
-//        al.add(3);
64
-//        al.add(4);
65
-//        al.add(2);
66
-//        al.add(0);
67
-//        al.add(1000);
68
-//        // When minMax is called
69
-//        Pair<Integer> result = Arrays.minMax(al);
70
-//        // Then it should return the first and last items
71
-//        Assert.assertEquals(new Integer(0), result.min());
72
-//        Assert.assertEquals(new Integer(1000), result.max());
73
-//    }
74
-//}
1
+package Pair;
2
+
3
+import org.junit.Assert;
4
+import org.junit.Test;
5
+
6
+import java.util.ArrayList;
7
+
8
+public class ArraysTest {
9
+    @Test
10
+    public void firstLast() throws Exception {
11
+        // Given an ArrayList of Integers
12
+        ArrayList<Integer> al = new ArrayList<>();
13
+        al.add(1);
14
+        al.add(5);
15
+        al.add(3);
16
+        al.add(4);
17
+        al.add(2);
18
+        al.add(0);
19
+        al.add(1000);
20
+        // When firstLast is called
21
+        Pair<Integer> result = Arrays.firstLast(al);
22
+        // Then it should return the first and last items
23
+        Assert.assertEquals(new Integer(1), result.getFirst());
24
+        Assert.assertEquals(new Integer(1000), result.getSecond());
25
+    }
26
+
27
+    @Test
28
+    public void testMin() throws Exception {
29
+        // Given an ArrayList of Integers
30
+        ArrayList<Integer> al = new ArrayList<>();
31
+        al.add(1);
32
+        al.add(5);
33
+        al.add(3);
34
+        al.add(4);
35
+        al.add(2);
36
+        al.add(0);
37
+        al.add(1000);
38
+        // When min is called assert that it gets the smallest item
39
+        Assert.assertEquals(new Integer(0), Arrays.min(al));
40
+    }
41
+
42
+    @Test
43
+    public void testMax() throws Exception {
44
+        // Given an ArrayList of Integers
45
+        ArrayList<Integer> al = new ArrayList<>();
46
+        al.add(1);
47
+        al.add(5);
48
+        al.add(3);
49
+        al.add(4);
50
+        al.add(2);
51
+        al.add(0);
52
+        al.add(1000);
53
+        // When min is called assert that it gets the largest item
54
+        Assert.assertEquals(new Integer(1000), Arrays.max(al));
55
+    }
56
+
57
+    @Test
58
+    public void testMinMax() throws Exception {
59
+        // Given an ArrayList of Integers
60
+        ArrayList<Integer> al = new ArrayList<>();
61
+        al.add(1);
62
+        al.add(5);
63
+        al.add(3);
64
+        al.add(4);
65
+        al.add(2);
66
+        al.add(0);
67
+        al.add(1000);
68
+        // When minMax is called
69
+        Pair<Integer> result = Arrays.minMax(al);
70
+        // Then it should return the first and last items
71
+        Assert.assertEquals(new Integer(0), result.min());
72
+        Assert.assertEquals(new Integer(1000), result.max());
73
+    }
74
+}

+ 32
- 32
src/test/java/Pair/PairTest.java View File

@@ -1,32 +1,32 @@
1
-//package Pair;
2
-//
3
-//import org.junit.Test;
4
-//import org.junit.Assert;
5
-//
6
-//public class PairTest {
7
-//
8
-//    @Test
9
-//    public void testGetters() throws Exception {
10
-//        // Given a pair with "Foo" and "Bar"
11
-//        Pair<String> p = new Pair<String>("Foo", "Bar");
12
-//        // When getFirst and getSecond are called, they should be returned.
13
-//        Assert.assertEquals("Foo", p.getFirst());
14
-//        Assert.assertEquals("Bar",  p.getSecond());
15
-//    }
16
-//
17
-//    @Test
18
-//    public void testMin() throws Exception {
19
-//        // Given a pair with two values
20
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
21
-//        // When p.min() is called, the smallest should be returned.
22
-//        Assert.assertEquals(new Double(1.23), p.min());
23
-//    }
24
-//
25
-//    @Test
26
-//    public void testMax() throws Exception {
27
-//        // Given a pair with two values
28
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
29
-//        // When p.max() is called, the largest should be returned.
30
-//        Assert.assertEquals(new Double(2.34), p.max());
31
-//    }
32
-//}
1
+package Pair;
2
+
3
+import org.junit.Test;
4
+import org.junit.Assert;
5
+
6
+public class PairTest {
7
+
8
+    @Test
9
+    public void testGetters() throws Exception {
10
+        // Given a pair with "Foo" and "Bar"
11
+        Pair<String> p = new Pair<String>("Foo", "Bar");
12
+        // When getFirst and getSecond are called, they should be returned.
13
+        Assert.assertEquals("Foo", p.getFirst());
14
+        Assert.assertEquals("Bar",  p.getSecond());
15
+    }
16
+
17
+    @Test
18
+    public void testMin() throws Exception {
19
+        // Given a pair with two values
20
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
21
+        // When p.min() is called, the smallest should be returned.
22
+        Assert.assertEquals(new Double(1.23), p.min());
23
+    }
24
+
25
+    @Test
26
+    public void testMax() throws Exception {
27
+        // Given a pair with two values
28
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
29
+        // When p.max() is called, the largest should be returned.
30
+        Assert.assertEquals(new Double(2.34), p.max());
31
+    }
32
+}