MartinAssignment.cs

public class Arrays
{
    public bool Find(int[] list, int value)
    {
        for (int i = 0; i < list.Length; i++)
        {
            if (list[i] == value) return true;
        }

        return false;
    }

    public int FindIndex(int[] list, int value)
    {
        for (int i = 0; i < list.Length; i++)
        {
            if (list[i] == value) return i;
        }

        return -1;
    }

    public int Count(int[] list, int value)
    {
        int amount = 0;
        for (int i = 0; i < list.Length; i++)
        {
            if (list[i] == value) amount++;
        }
        return amount;
    }

    public int Sum(int[] list)
    {
        int result = 0;

        for (int i = 0; i < list.Length; i++)
        {
            result += i;
        }

        return result;
    }

    public int Max(int[] list)
    {
        int result = int.MinValue;

        for (int i = 0; i < list.Length; i++)
        {
            if (list[i] > result) result = list[i];
        }

        return result;
    }

    public int Min(int[] list)
    {
        int result = int.MaxValue;

        for (int i = 0; i < list.Length; i++)
        {
            if (list[i] < result) result = list[i];
        }

        return result;
    }

    public bool IsOrdered(int[] list)
    {
        for (int i = 1; i < list.Length; i++)
        {
            if (list[i] < list[i - 1]) return false;
        }

        return true;
    }

    public string Display(int[] list)
    {
        string str = "";

        for (int i = 0; i < list.Length; i++)
        {
            str += list[i] + " ";
        }

        return str;
    }

    public void Swap(int[] list, int i, int j)
    {
        int temp = list[i];
        list[i] = list[j];
        list[j] = temp;
    }

    public bool HasDuplicates(int[] list)
    {
        for (int i = 0; i < list.Length; i++)
        {
            for (int j = i+1; j < list.Length; j++)
            {
                if (list[i] == list[j])
                {
                    return true;
                }
            }
        }

        return false;
    }

    public void Sort(int[] list)
    {
        for (int i = 0; i < list.Length; i++)
        {
            for (int j = i + 1; j < list.Length; j++)
            {
                if (list[i] > list[j])
                {
                    Swap(list, i, j);
                }
            }
        }
    }

    public int[] Combine(int[] list1, int[] list2)
    {
        int[] result = new int[list1.Length + list2.Length];

        for (int i = 0; i < list1.Length; i++)
        {
            result[i] = list1[i];
        }

        for (int j = 0; j < list2.Length; j++)
        {
            result[j + list1.Length] = list2[j];
        }

        return result;
    }

    public void Reverse(int[] list)
    {
        int lastIndex = list.Length - 1;

        for (int i = 0; i < list.Length/2; i++)
        {
            Swap(list, i, lastIndex);
            lastIndex--;
        }
    }
}

[TestClass]
public class ArraysTest
{

    private Arrays A { get; } = new Arrays();

    [TestMethod]
    public void SwapTest()
    {
        int[] list = new[] {1, 2, 3, 4, 5};

        A.Swap(list, 0, 4);

        CollectionAssert.AreEqual(new[]{5,2,3,4,1}, list);
    }

    [TestMethod]
    public void DuplicateTest()
    {
        int[] list = new[] {1, 2, 3, 4, 5};
        int[] listWithDuplicates = new[] {1, 0, 2, 3, 1};

        Assert.IsTrue(A.HasDuplicates(listWithDuplicates));
        Assert.IsFalse(A.HasDuplicates(list));
    }

    [TestMethod]
    public void SortTest()
    {
        int[] list = new[] {1, 4, 5, 3, 2};
        int[] sortedList = new[] {1, 2, 3, 4, 5};

        A.Sort(list);

        CollectionAssert.AreEqual(list, sortedList);
    }

    [TestMethod]
    public void CombineTest()
    {
        int[] list1 = new[] {1, 2, 3, 4};
        int[] list2 = new[] {5, 6, 7, 8};

        CollectionAssert.AreEqual(A.Combine(list1, list2), new[] {1,2,3,4,5,6,7,8});
    }

    [TestMethod]
    public void ReverseTest()
    {
        int[] list = new[] {1, 2, 3, 4, 5};
        int[] reverseList = new[] {5, 4, 3, 2, 1};

        A.Reverse(list);

        CollectionAssert.AreEqual(list, reverseList);
    }

    [TestMethod]
    public void CountTest()
    {
        int[] list = new[] {1, 1, 1, 2, 3, 4, 5, 5, 5, 5, 5, 5, 5};

        Assert.IsTrue(A.Count(list, 1) == 3);
        Assert.IsTrue(A.Count(list, 5) == 7);
    }
}