44 lines
1.2 KiB
C#
44 lines
1.2 KiB
C#
using System.Numerics;
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using System.Runtime.CompilerServices;
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namespace Recyclable.Collections
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{
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public static class MathUtils
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{
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// private static readonly long[] Pow2 = new long[]
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// {
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// 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384,
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// 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304,
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// 8388608, 16777216, 33554432, 67108864, 134217728, 268435456,
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// 536870912, 1073741824, 2147483648
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// };
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static bool IsPow2(long value) => (value != 0) && ((value & (value - 1)) == 0);
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static int GetPow2Shift(long value) => BitOperations.IsPow2(value) ? 63 - BitOperations.LeadingZeroCount((ulong)value) : -1;
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static long DivMod(long number, int divider, out long remainder)
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{
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if (number >= divider << 4)
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{
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return Math.DivRem(number, divider, out remainder);
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}
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else
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{
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int result = 0;
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remainder = number;
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while (remainder >= divider)
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{
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remainder -= divider;
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result++;
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}
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return result;
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}
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}
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}
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}
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