public void BinarySearchWithIndexFindsElementInRange(int index, int count)
{
var size = SampleSize;
var old = new T[size];
var even = new T[size];
for (int i = size - 1; i >= 0; i--)
{
// offset from 5 to get double digits so that elements are in
// sort order of string.
old[i] = TestData <T> .MakeData((i + 5) *2 + 1);
even[i] = TestData <T> .MakeData((i + 5) * 2);
}
var min = TestData <T> .One;
var max = TestData <T> .MakeData((size + 5) * 2);
var sut = new CopyOnWriteList <T>(even);
// This shoud trigger any argument exception
Assert.That(sut.BinarySearch(index, count, min, null), Is.EqualTo(-(index + 1)));
Assert.That(sut.BinarySearch(index, count, max, null), Is.EqualTo(-(index + count + 1)));
for (int i = 0; i < count; i++)
{
var j = index + i;
var result = sut.BinarySearch(index, count, even[j], null);
Assert.That(result, Is.EqualTo(j));
result = sut.BinarySearch(index, count, old[j], null);
Assert.That(result, Is.EqualTo(-j - 2));
}
sut.Reverse();
Assert.That(sut.BinarySearch(index, count, max, _reverseComparer), Is.EqualTo(-(index + 1)));
Assert.That(sut.BinarySearch(index, count, min, _reverseComparer), Is.EqualTo(-(index + count + 1)));
for (int i = 0; i < count; i++)
{
var j = index + i;
var result = sut.BinarySearch(index, count, even[size - 1 - j], _reverseComparer);
Assert.That(result, Is.EqualTo(j));
result = sut.BinarySearch(index, count, old[size - 1 - j], _reverseComparer);
Assert.That(result, Is.EqualTo(-j - 1));
}
}
[Test] public void BinarySearchFindsElements()
{
var size = SampleSize;
T[] samples = NewPsuedoRandomSamples();
var before = TestData <T> .Zero;
var after = TestData <T> .MakeData(size);
Array.Sort(samples);
var sut = new CopyOnWriteList <T>(samples);
Assert.That(sut.BinarySearch(before), Is.EqualTo(-1));
Assert.That(sut.BinarySearch(after), Is.EqualTo(-size - 1));
var defaultComparer = Comparer <T> .Default;
for (int i = 0; i <= size; i++)
{
var item = TestData <T> .MakeData(i);
var index = sut.BinarySearch(item);
if (index >= 0)
{
Assert.That(sut[index], Is.EqualTo(item));
}
else
{
index = -index - 1;
if (index > 0)
{
Assert.That(defaultComparer.Compare(sut[index - 1], item), Is.LessThan(0));
}
if (index < size)
{
Assert.That(defaultComparer.Compare(sut[index], item), Is.GreaterThan(0));
}
}
}
Array.Sort(samples, _reverseComparer);
sut = new CopyOnWriteList <T>(samples);
Assert.That(sut.BinarySearch(before, _reverseComparison), Is.EqualTo(-size - 1));
Assert.That(sut.BinarySearch(after, _reverseComparison), Is.EqualTo(-1));
for (int i = 0; i <= size; i++)
{
var item = TestData <T> .MakeData(i);
var index = sut.BinarySearch(item, _reverseComparison);
if (index >= 0)
{
Assert.That(sut[index], Is.EqualTo(item));
}
else
{
index = -index - 1;
if (index > 0)
{
Assert.That(_reverseComparison(sut[index - 1], item), Is.LessThan(0));
}
if (index < size)
{
Assert.That(_reverseComparison(sut[index], item), Is.GreaterThan(0));
}
}
}
}
