public void Challenge08_DetectEcb()
{
var lines = File.ReadAllLines("8.txt");
var candidates = new Dictionary <int, double>(lines.Length);
for (var i = 0; i < lines.Length; i++)
{
var line = lines[i];
var cipher = Hex.ToBytes(line);
var same = new HashSet <int>(cipher.Length / 16);
for (int segment1 = 0; segment1 < cipher.Length / 16; ++segment1)
{
if (same.Contains(segment1))
{
continue;
}
for (int segment2 = segment1 + 1; segment2 < cipher.Length / 16; ++segment2)
{
if (same.Contains(segment2))
{
continue;
}
if (0 == Hamming.GetDistance(cipher.AsSpan(segment1 * 16, 16), cipher.AsSpan((segment2) * 16, 16)))
{
same.Add(segment1);
same.Add(segment2);
}
}
}
candidates[i + 1] = same.Count;
}
var lnNr = candidates.OrderByDescending(x => x.Value).First().Key;
Assert.Equal(133, lnNr);
}
public void GetHammingDistance_EmptyStrands_DistanceIsZero()
{
Assert.AreEqual(0, Hamming.GetDistance(string.Empty, string.Empty));
}
public void GetHammingDistance_SecondStrandLonger_ThrowsArgumentException()
{
Assert.Throws <ArgumentException>(() => Hamming.GetDistance("ATA", "AGTG"));
}
public void GetHammingDistance_FirstStrandLonger_ThrowsArgumentException()
{
Assert.Throws <ArgumentException>(() => Hamming.GetDistance("AATG", "AAA"));
}
public void GetHammingDistance_OneNonUniqueCharacterInStrand_DistanceIsOne()
{
Assert.AreEqual(1, Hamming.GetDistance("AAA", "AAG"));
}
public void GetHammingDistance_LongStrandsWithTwoDifference_DistanceIsTwo()
{
Assert.AreEqual(2, Hamming.GetDistance("ACCAGGG", "ACTATGG"));
}
public void GetHammingDistance_SmallStrandsWithTwoDifference_DistanceIsTwo()
{
Assert.AreEqual(2, Hamming.GetDistance("AG", "CT"));
}
public void GetHammingDistance_SmallStrandsWithOneDifference_DistanceIsOne()
{
Assert.AreEqual(1, Hamming.GetDistance("AT", "CT"));
}
public void GetHammingDistance_OneDifference_DistanceOne()
{
Assert.AreEqual(1, Hamming.GetDistance("A", "G"));
}
public void GetHammingDistance_IdenticalStrands_DistanceIsZero(string strand)
{
Assert.AreEqual(0, Hamming.GetDistance(strand, strand));
}
