Question

我的任务是搜索数字的二进制表示，并替换数字的另一个二进制表示的匹配模式。如果我得到匹配，我将第一个整数的匹配位转换为零并继续。例如，数字469将是meteor add http，我必须将其与5（111010101）匹配。这是我迄今为止编写的程序。没有按预期工作。

Answer 1

少数事情：

使用uint。在处理二进制数时，使事情变得更加容易。
你并没有真正设置任何东西 - 你只是存储信息，这就是你经常打印相同数字的原因。
你应该循环x次，其中x =二进制字符串的长度（不仅仅是29）。没有内循环

static void Main(string[] args)
{
    //this is the number I'm searching for a match in
    uint binaryTicket = 469;
    //This is the pattern I'm trying to match (101)
    uint binaryPerforator = 5;

    var numBinaryDigits = Math.Ceiling(Math.Log(binaryTicket, 2));
    for (var i = 0; i < numBinaryDigits; i++)
    {
        var perforatorShifted = binaryPerforator << i;

        //We need to mask off the result (otherwise we fail for checking 101 -> 111)
        //The mask will put 1s in each place the perforator is checking.
        var perforDigits = (int)Math.Ceiling(Math.Log(perforatorShifted, 2));
        uint mask = (uint)Math.Pow(2, perforDigits) - 1;

        Console.WriteLine("Ticket:\t" + GetBinary(binaryTicket));
        Console.WriteLine("Perfor:\t" + GetBinary(perforatorShifted));
        Console.WriteLine("Mask :\t" + GetBinary(mask));

        if ((binaryTicket & mask) == perforatorShifted)
        {
            Console.WriteLine("Match.");
            //Imagine we have the case:

            //Ticket:
            //111010101
            //Perforator:
            //000000101

            //Is a match. What binary operation can we do to 0-out the final 101?
            //We need to AND it with 
            //111111010

            //To get that value, we need to invert the perforatorShifted
            //000000101
            //XOR
            //111111111
            //EQUALS
            //111111010

            //Which would yield:
            //111010101
            //AND
            //111110000
            //Equals
            //111010000

            var flipped = perforatorShifted ^ ((uint)0xFFFFFFFF);
            binaryTicket = binaryTicket & flipped;
        }
    }

    string binaryTicket01 = Convert.ToString(binaryTicket, 2);
    Console.WriteLine(binaryTicket01);
}

static string GetBinary(uint v)
{
    return Convert.ToString(v, 2).PadLeft(32, '0');
}

请仔细阅读以上代码 - 如果您有任何不明白之处，请给我留言，我可以和您一起完成。

匹配数字中的一系列位，然后将匹配转换为零？

1 个答案: