public void Dft_Convolution_Many()
{
var a = Enumerable.Range(3, 1 << 16).Select(x => (long)x).ToArray();
var b = Enumerable.Range(7, 1 << 16).Select(x => (long)x).ToArray();
Dft.Convolution(a, b);
}
protected override Task ProcessRemoving(CancellationToken ct)
{
return(Task.Run(async() =>
{
var p = ReadParameters();
var algorithm = new Dft(p);
var result = algorithm.RemoveWatermark(ct);
await ShowAlgorithmOutput(result);
}));
}
public void Convolution()
{
var a = new long[] { 1, 2, 3, 4 };
var b = new long[] { 5, 6, 7, 8, 9 };
var expected = new long[] { 5, 16, 34, 60, 70, 70, 59, 36 };
CollectionAssert.AreEqual(expected, Dft.Convolution(a, b));
CollectionAssert.AreEqual(expected, Dft0.Convolution(a, b));
CollectionAssert.AreEqual(expected, Ntt.Convolution(a, b));
CollectionAssert.AreEqual(expected, Ntt0.Convolution(a, b));
}
// 長さは n 以下で OK。
public static Complex[] Convolution(Complex[] a, Complex[] b)
{
var dft = new Dft(a.Length + b.Length - 1);
var fa = dft.Fft(a);
var fb = dft.Fft(b);
for (int i = 0; i < dft.n; ++i)
{
fa[i] *= fb[i];
}
return(dft.Fft(fa, true));
}
public void Dft_Fft_Many()
{
var n = 1 << 16;
var a = Enumerable.Range(3, n).ToArray();
var c = Array.ConvertAll(a, x => new Complex(x, 0));
var dft = new Dft(n);
var t = dft.Fft(c);
var r = dft.Fft(t, true).ToInt();
CollectionAssert.AreEqual(a, r);
}
protected override Task ProcessAdding(CancellationToken ct)
{
return(Task.Run(async() =>
{
ct.ThrowIfCancellationRequested();
var p = ReadParameters();
ct.ThrowIfCancellationRequested();
var algorithm = new Dft(p);
var result = algorithm.AddWatermark(ct);
await ShowAlgorithmOutput(result);
}));
}
public void Setup()
{
originalBitmap = new Bitmap(resourcesPath + "c_corgi.png");
watermarkBitmap = new Bitmap(resourcesPath + "w_tekst_dolny.png");
expectedDftBitmap = new Bitmap(myResourcesPath + "original_fourier_test.png");
expectedDftWatermarkedBitmap = new Bitmap(myResourcesPath + "fourier_watermarked_test.png");
expectedWatermarkedBitmap = new Bitmap(myResourcesPath + "dft_watermarked_test.png");
key = 10;
alpha = 0.01M;
parameters = new DftParameters(originalBitmap.TransformToEffectiveBitmap(), watermarkBitmap.TransformToEffectiveBitmap(), null, key, alpha);
algorithm = new Dft(parameters);
}
public void Dft_Fft()
{
var n = 1 << 4;
var a = Enumerable.Range(3, n).ToArray();
var c = Array.ConvertAll(a, x => new Complex(x, 0));
var t0 = Dft0.Naive(c);
var r0 = Dft0.Naive(t0, true).ToInt();
var t1 = Dft0.Fft(c);
var r1 = Dft0.Fft(t1, true).ToInt();
var dft = new Dft(n);
var t2 = dft.Fft(c);
var r2 = dft.Fft(t2, true).ToInt();
CollectionAssert.AreEqual(a, r0);
CollectionAssert.AreEqual(a, r1);
CollectionAssert.AreEqual(a, r2);
}
static void Main()
{
var h = ReadL();
long n = h[0], m = h[1];
var a = ReadL();
var c = Tally(a, a.Max());
var conv = Dft.Convolution(c, c);
long r = 0, count = 0;
for (int x = conv.Length - 1; x >= 0 && count < m; x--)
{
if (conv[x] == 0)
{
continue;
}
var nc = Math.Min(m, count + conv[x]);
r += x * (nc - count);
count = nc;
}
Console.WriteLine(r);
}
public void TestOptimalDftSize()
{
var optimalSize = Dft.GetOptimalSize(98);
Assert.AreEqual(100, optimalSize);
}