private long Hash(K key)
{
var bytes = transform(key);
var hash = hasher.Hash(bytes);
return(hash[0]);
}
public static int HashSolution(string salt, IHashStrategy hashStrategy)
{
var keys = new List <string>();
var hashCache = new Dictionary <int, string>();
string GetHash(int index)
{
if (!hashCache.ContainsKey(index))
{
hashCache[index] = hashStrategy.Hash(salt + index);
}
return(hashCache[index]);
}
for (int index = 0;; index++)
{
var hash = hashStrategy.Hash(salt + index);
var c = FirstRepeatedCharacter(hash, 3);
if (c.HasValue)
{
for (int promoteIndex = index + 1; promoteIndex < index + 1000; promoteIndex++)
{
string promotionHash = GetHash(promoteIndex);
var fiveC = Enumerable.Repeat(c.Value, 5);
if (promotionHash.Contains(new string(fiveC.ToArray())))
{
keys.Add(hash);
if (keys.Count == 64)
{
return(index);
}
break;
}
}
}
}
}
public float[,] PerformAvalancheTest(int numSamples)
{
var flipCounts = new int[NumInputBits, NumOutputBits];
for (var runNumber = 0; runNumber < numSamples; runNumber++)
{
byte[] initial = new byte[_numInputBytes];
_random.NextBytes(initial);
T hash1 = _hashStrategy.Hash(initial);
for (var i = 0; i < NumInputBits; i++)
{
byte bitMaskForByteFlip = (byte)(0x1 << (i % 8));
initial[i / 8] ^= bitMaskForByteFlip;
T hash2 = _hashStrategy.Hash(initial);
initial[i / 8] ^= bitMaskForByteFlip;
for (var j = 0; j < NumOutputBits; j++)
{
if (_bitOperator.BitAt(hash1, j) != _bitOperator.BitAt(hash2, j))
{
flipCounts[i, j]++;
}
}
}
}
var flipRanges = new float[NumInputBits, NumOutputBits];
for (var i = 0; i < NumInputBits; i++)
{
for (var j = 0; j < NumOutputBits; j++)
{
flipRanges[i, j] = (float)flipCounts[i, j] / numSamples;
}
}
return(flipRanges);
}
