A Fast Random Number Generator Based on BigInteger<\/p>\n\n\n\n
using System;\nusing System.Numerics;\nusing System.Security.Cryptography;\npublic struct RandomX\n{\n private readonly RNGCryptoServiceProvider _crng;\n private int _maxByteWidth;\n private int _bitWidth;\n public RandomX(int bitWidth)\n {\n MaxValue = BigIntegerHelper.GetMaxValueBitWidth(bitWidth);\n _maxByteWidth = bitWidth >> 3;\n OddsOnly = false;\n Unsigned = false;\n _crng = new RNGCryptoServiceProvider();\n _bitWidth = bitWidth;\n }\n public bool OddsOnly;\n public bool Unsigned;\n public int BitWidth\n {\n get => _bitWidth;\n set\n {\n _bitWidth = value;\n MaxValue = BigIntegerHelper.GetMaxValueBitWidth(_bitWidth);\n _maxByteWidth = _bitWidth >> 3;\n }\n }\n public BigInteger MaxValue;\n public bool NextBool()\n {\n return Sample() < .5;\n }\n public char NextChar(char maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (char) (Sample() * maxValue);\n }\n public char NextChar(char minValue, char maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (char) Next(minValue, maxValue);\n }\n public sbyte NextInt8()\n {\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 8)\n BitWidth = 8;\n return (sbyte) Internal();\n }\n public sbyte NextInt8(sbyte maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 8)\n BitWidth = 8;\n return (sbyte) (Sample() * maxValue);\n }\n public sbyte NextInt8(sbyte minValue, sbyte maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 8)\n BitWidth = 8;\n return (sbyte) Next(minValue, maxValue);\n }\n public byte NextUInt8()\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 8)\n BitWidth = 8;\n var n = Internal();\n return (byte) n;\n }\n public byte NextUInt8(byte maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 8)\n BitWidth = 8;\n return (byte) (Sample() * maxValue);\n }\n public byte NextUInt8(byte minValue, byte maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 8)\n BitWidth = 8;\n return (byte) Next(minValue, maxValue);\n }\n public short NextInt16()\n {\n if (_bitWidth < 16)\n BitWidth = 16;\n if (Unsigned)\n Unsigned = false;\n return (short) Internal();\n }\n public short NextInt16(short maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (short) (Sample() * maxValue);\n }\n public short NextInt16(short minValue, short maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (short) Next(minValue, maxValue);\n }\n public ushort NextUInt16()\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (ushort) Internal();\n }\n public ushort NextUInt16(ushort maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (ushort) (Sample() * maxValue);\n }\n public ushort NextUInt16(ushort minValue, ushort maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 16)\n BitWidth = 16;\n return (ushort) Next(minValue, maxValue);\n }\n public int NextInt24()\n {\n BitWidth = 24;\n if (Unsigned)\n Unsigned = false;\n return (int) Internal();\n }\n public int NextInt24(int maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 24;\n return (int) (Sample() * maxValue);\n }\n public int NextInt24(int minValue, int maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 24;\n return (int) Next(minValue, maxValue);\n }\n public uint NextUInt24()\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 24;\n return (uint) Internal();\n }\n public uint NextUInt24(uint maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 24;\n return (uint) (Sample() * maxValue);\n }\n public uint NextUInt24(uint minValue, uint maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 24;\n return (uint) Next(minValue, maxValue);\n }\n public uint NextUInt32()\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (uint) Internal();\n }\n public uint NextUInt32(uint maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (uint) (Sample() * maxValue);\n }\n public uint NextUInt32(uint minValue, uint maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (uint) Next(minValue, maxValue);\n }\n public int NextInt32()\n {\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (int) Internal();\n }\n public int NextInt32(int maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (int) (Sample() * maxValue);\n }\n public int NextInt32(int minValue, int maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 32)\n BitWidth = 32;\n return (int) Next(minValue, maxValue);\n }\n public long NextUInt40()\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 40;\n return (long) Internal();\n }\n public long NextUInt40(long maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 40;\n return (long) (Sample() * maxValue);\n }\n public long NextUInt40(long minValue, long maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 40;\n return (long) Next(minValue, maxValue);\n }\n public long NextInt40()\n {\n if (Unsigned)\n Unsigned = false;\n BitWidth = 40;\n return (long) Internal();\n }\n public long NextInt40(long maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 40;\n return (long) (Sample() * maxValue);\n }\n public long NextInt40(long minValue, long maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 40;\n return (long) Next(minValue, maxValue);\n }\n public ulong NextUInt48()\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 48;\n return (ulong) Internal();\n }\n public ulong NextUInt48(ulong maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 48;\n return (ulong) (Sample() * maxValue);\n }\n public ulong NextUInt48(ulong minValue, ulong maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 48;\n return (ulong) Next(minValue, maxValue);\n }\n public long NextInt48()\n {\n if (Unsigned)\n Unsigned = false;\n BitWidth = 48;\n return (long) Internal();\n }\n public long NextInt48(long maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 48;\n return (long) (Sample() * maxValue);\n }\n public ulong NextUInt56()\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 56;\n return (ulong) Internal();\n }\n public ulong NextUInt56(ulong maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 56;\n return (ulong) (Sample() * maxValue);\n }\n public ulong NextUInt56(ulong minValue, ulong maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n BitWidth = 56;\n return (uint) Next(minValue, maxValue);\n }\n public long NextInt56()\n {\n if (Unsigned)\n Unsigned = false;\n BitWidth = 56;\n return (long) Internal();\n }\n public long NextInt56(long maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 56;\n return (long) (Sample() * maxValue);\n }\n public long NextInt56(long minValue, long maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n BitWidth = 48;\n return (long) Next(minValue, maxValue);\n }\n public long NextInt64()\n {\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (long) Internal();\n }\n public long NextInt64(long maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (long) (Sample() * maxValue);\n }\n public long NextInt64(long minValue, long maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (Unsigned)\n Unsigned = false;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (long) Next(minValue, maxValue);\n }\n public ulong NextUInt64()\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (ulong) Internal();\n }\n public ulong NextUInt64(ulong maxValue)\n {\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (ulong) (Sample() * maxValue);\n }\n public ulong NextUInt64(ulong minValue, ulong maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n if (!Unsigned)\n Unsigned = true;\n if (_bitWidth < 64)\n BitWidth = 64;\n return (ulong) Next(minValue, maxValue);\n }\n public BigInteger Next()\n {\n return Internal();\n }\n public BigInteger Next(BigInteger minValue, BigInteger maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n return (BigInteger) (Sample() * (maxValue - minValue)) + minValue;\n }\n public UInt512 Next(UInt512 minValue, UInt512 maxValue)\n {\n if (minValue > maxValue)\n throw new ArgumentException(\"maxValue must be greater than or equal to minValue\");\n var s = Sample();\n var f = (BigDecimal) ((BigInteger) maxValue - (BigInteger) minValue);\n return (BigInteger) (s * f);\n }\n public BigInteger Next(BigInteger maxValue)\n {\n if (maxValue < 0)\n throw new ArgumentException(\"maxValue must be greater than zero.\");\n return (BigInteger) (Sample() * maxValue);\n }\n public unsafe double NextDouble()\n {\n var buf = new byte[8];\n GetBytes(buf);\n fixed (byte* ptr = buf)\n {\n return *(ulong*) ptr * (1.0 \/ ulong.MaxValue) * ulong.MaxValue;\n }\n }\n public BigRational NextBigRational()\n {\n return new BigRational(Internal(), Internal());\n }\n public decimal NextDecimal()\n {\n return new decimal(NextInt32(), NextInt32(), NextInt32(), NextBool(), NextUInt8(255));\n }\n public BigDecimal NextBigDecimal()\n {\n return Sample();\n }\n public byte[] GetNextByteArray(int size)\n {\n var ba = new byte[size];\n _crng.GetBytes(ba);\n return ba;\n }\n public char[] GetNextCharArray(int size)\n {\n var xbc = new byte[1];\n var ca = new char[size];\n var ptr = 0;\n do\n {\n _crng.GetBytes(xbc);\n var c = xbc[0];\n if (c >= 0x20 && c <= 0x7F)\n ca[ptr++] = (char) c;\n } while (ptr < size);\n return ca;\n }\n public char NextChar()\n {\n var xbc = new byte[1];\n while (true)\n {\n _crng.GetBytes(xbc);\n var c = xbc[0];\n if (c >= 0x20 && c <= 0x7F)\n return (char) c;\n }\n }\n public string GetRandomString(int minLen, int maxLen)\n {\n return minLen == maxLen ? new string(GetNextCharArray(minLen)) : new string(GetNextCharArray((int) NextUInt32((uint) minLen, (uint) maxLen)));\n }\n private BigDecimal Sample()\n {\n var i = Internal();\n var s = i * (BigDecimal.One \/ MaxValue);\n if (s.Sign == -1)\n s = s * -1;\n if (s.IsZero)\n throw new Exception(\"Sample is zero.\");\n return s;\n }\n public void GetBytes(byte[] data)\n {\n if (data == null)\n throw new ArgumentException(\"The buffer cannot be null.\");\n _crng.GetBytes(data);\n }\n private BigInteger Internal()\n {\n if (Unsigned)\n {\n var buffer = new byte[_maxByteWidth + 1];\n _crng.GetBytes(buffer);\n buffer[_maxByteWidth] = 0;\n var n = new BigInteger(buffer);\n return !OddsOnly ? n : n | 1;\n }\n else\n {\n var buffer = new byte[_maxByteWidth];\n _crng.GetBytes(buffer);\n var n = new BigInteger(buffer);\n return !OddsOnly ? n : n | 1;\n }\n }\n}<\/pre>\n","protected":false},"excerpt":{"rendered":"A Fast Random Number Generator Based on 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