zoukankan      html  css  js  c++  java
  • [转]C# BitReverse 和 Java BitReverse 可以互转

    1.含义

    根据长整型的存储形式,根据高地位作为参考,进行按位互换。并输出按位翻转后的结果值。

    例如:

    0100 1011 翻转为 1101 0010

    高位:0100 翻转为低位 0010

    低位:1011 翻转为高位 1101

    翻转后结果为 1101[高位] 0010[低位]

    注:此算法为可逆算法。即数据执行2次翻转后,其值必须等于原值!此算法可被用于数据离散存储场景中。用于解决连续数据无法被离散存储的方式之一。

    2.可行性源代码(非最优化代码)

    public sealed class BitReverse
    {
    protected static int[] BitReverseTable256 =
    {
    0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0,
    0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8,
    0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4,
    0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC,
    0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2,
    0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA,
    0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6,
    0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE,
    0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1,
    0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9,
    0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5,
    0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD,
    0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3,
    0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB,
    0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
    0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
    };

    /// <summary>
    /// According to a reverse.
    /// e.g: 0010 0000(source) => 0000 0100(dest)
    /// </summary>
    /// <remarks>This is a reversible algorithm. original data -reserved-> dest value -reserved-> original value </remarks>
    /// <param name="input">source</param>
    /// <returns>reversed data</returns>
    public static long Convert(long input)
    {
    return (BitReverseTable256[input & 0xff] << 24) | (BitReverseTable256[(input >> 8) & 0xff] << 16) | (BitReverseTable256[(input >> 16) & 0xff] << 8) | (BitReverseTable256[(input >> 24) & 0xff]);
    }
    }

  • 相关阅读:
    HDU 5213 分块 容斥
    HDU 2298 三分
    HDU 5144 三分
    HDU 5145 分块 莫队
    HDU 3938 并查集
    HDU 3926 并查集 图同构简单判断 STL
    POJ 2431 优先队列
    HDU 1811 拓扑排序 并查集
    HDU 2685 GCD推导
    HDU 4496 并查集 逆向思维
  • 原文地址:https://www.cnblogs.com/geraint999/p/4610569.html
Copyright © 2011-2022 走看看