/// <summary>
/// Finds the max item in the collection. if max items are repeted then it
/// will return first one
/// return the first one
/// </summary>
public static T FindMax <T>(IEnumerable <T> collection,
ComparerFunc <T> comparer)
{
var enumerator = collection.GetEnumerator();
T max;
if (enumerator.MoveNext())
{
max = enumerator.Current;
while (enumerator.MoveNext())
{
T t = enumerator.Current;
if (comparer(t, max) > 0)
{
// t is greater than max, update max
max = t;
}
}
}
else
{
throw new ApplicationException("not a valid collection");
}
return(max);
}
public static List <TElement> Sort <TElement, TKey>(this List <TElement> list, Func <TElement, TKey> key) where TKey : IComparable <TKey>
{
var comparer = new ComparerFunc <TElement>((x, y) => key(x).CompareTo(key(y)));
list.Sort(comparer);
return(list);
}
/// <summary>
/// Finds the min item in the collection. if min items are repeated then it
/// will return first one
/// </summary>
public static T FindMin <T>(IEnumerable <T> collection,
ComparerFunc <T> comparer)
{
IEnumerator <T> enumerator = collection.GetEnumerator();
T min;
if (enumerator.MoveNext())
{
min = enumerator.Current;
while (enumerator.MoveNext())
{
T t = enumerator.Current;
if (comparer(t, min) < 0)
{
// t is less that than min, update max
min = t;
}
}
}
else
{
throw new ApplicationException("Not a valid collection");
}
return(min);
}
public void SortWithFuncDelegate(int[] firstRow, int[] secondRow, int[] thirdRow, int[] fouthRow)
{
int[][] actual = new int[4][];
actual[0] = fouthRow;
actual[1] = thirdRow;
actual[2] = firstRow;
actual[3] = secondRow;
ComparerSumIncrease sumInc = new ComparerSumIncrease();
Func <int[], int[], int> predicate = (sumInc.Compare);
ComparerFunc comparerFunc = new ComparerFunc(predicate);
BubbleSort(actual, comparerFunc);
int[][] expected = new int[4][];
expected[0] = thirdRow;
expected[1] = secondRow;
expected[2] = fouthRow;
expected[3] = firstRow;
BubbleSort(actual, predicate);
}
public void TestOrderByComparerPreserved()
{
var sequence = Enumerable.Range(1, 100);
var sequenceAscending = sequence.Select(x => x.ToString());
var sequenceDescending = sequenceAscending.Reverse();
var comparer = new ComparerFunc<string>((a, b) => int.Parse(a).CompareTo(int.Parse(b)));
var resultAsc1 = sequenceAscending.OrderBy(x => x, comparer, OrderByDirection.Descending);
var resultAsc2 = sequenceAscending.OrderByDescending(x => x, comparer);
// ensure both order by operations produce identical results
Assert.IsTrue(resultAsc1.SequenceEqual(resultAsc2));
// ensure comparer was applied in the order by evaluation
Assert.IsTrue(resultAsc1.SequenceEqual(sequenceDescending));
var resultDes1 = sequenceDescending.OrderBy(x => x, comparer, OrderByDirection.Ascending);
var resultDes2 = sequenceDescending.OrderBy(x => x, comparer);
// ensure both order by operations produce identical results
Assert.IsTrue(resultDes1.SequenceEqual(resultDes2));
// ensure comparer was applied in the order by evaluation
Assert.IsTrue(resultDes1.SequenceEqual(sequenceAscending));
}
public int Compare_Absolute_Tests(int a, int b, int c, int d, int e)
{
Func <int, int, int> absoluteComparerFunc = (x, y) =>
{
if (Math.Abs(x) > Math.Abs(y))
{
return(1);
}
if (Math.Abs(x) < Math.Abs(y))
{
return(-1);
}
return(0);
};
var list = new[] { a, b, c, d, e };
var sortedList = list.OrderBy(z => z, ComparerFunc <int> .Create(absoluteComparerFunc))
.ToList();
return(sortedList.Last());
}
public string Compare_OrderBy_Tests(int a, int b, int c, int d, int e)
{
Func <int, int, int> evensFirst = (x, y) =>
{
if (x == y)
{
return(0);
}
if (x % 2 == y % 2)
{
return(x < y ? -1 : 1);
}
return((x % 2 == 0) ? -1 : 1);
};
var list = new[] { a, b, c, d, e };
var sortedList = list.OrderBy(z => z, ComparerFunc <int> .Create(evensFirst))
.ToList();
return(string.Join(",", sortedList.Select(x => x.ToString())));
}
Comparer(ComparerFunc f)
{
this.cmp = f;
}
Comparer (ComparerFunc f)
{
this.cmp = f;
}
public void TestThenByComparerPreserved()
{
var sequence = new[]
{
new {A = "2", B = "0"},
new {A = "1", B = "5"},
new {A = "2", B = "2"},
new {A = "1", B = "3"},
new {A = "1", B = "4"},
new {A = "2", B = "1"},
};
var comparer = new ComparerFunc<string>((a, b) => int.Parse(a).CompareTo(int.Parse(b)));
var resultA1 = sequence.OrderBy(x => x.A, comparer, OrderByDirection.Ascending)
.ThenBy(y => y.B, comparer, OrderByDirection.Ascending);
var resultA2 = sequence.OrderBy(x => x.A, comparer)
.ThenBy(y => y.B, comparer);
// ensure both produce the same order
Assert.IsTrue(resultA1.SequenceEqual(resultA2));
var resultB1 = sequence.OrderBy(x => x.A, comparer, OrderByDirection.Ascending)
.ThenBy(y => y.B, comparer, OrderByDirection.Descending);
var resultB2 = sequence.OrderBy(x => x.A, comparer)
.ThenByDescending(y => y.B, comparer);
// ensure both produce the same order
Assert.IsTrue(resultB1.SequenceEqual(resultB2));
}
