进制之间的任意转换

进制之间的任意转换

一、10进制数转换任意进制的数

基本思路：求余数，直到被除数/进制=0，然后按逆序排列。

C#:

 1  static void TestMath_6(string number, int scale)
 2         {
 3             int length = number.Length;
 4             int num = 0;
 5             int gt = 0;
 6             for (int i = 0; i < length; i++)
 7             {
 8                 if (number[i] >= 'a')
 9                 {
10                     gt = number[i] - 'a' + 10;
11                 }
12                 else if (number[i] >= 'A')
13                 {
14                     gt = number[i] - 'A' + 10;
15                 }//每个位置的数
16                 else if (number[i] >= '0')
17                 {
18                     gt = number[i] - '0';
19 
20                 }
21                 num += gt * (int)(Math.Pow(scale, (length - i - 1)));
22             }
23             Console.WriteLine("{0}={1}", number, num);
24 
25         }

 1 //优化代码
 2         static void TestMath_5(int number, int scale)//number除数，scale进制
 3         {
 4             int mynumber = number;
 5             string mystr = null;
 6             char[] mychar = new char[100];
 7             int j = 0;
 8              do 
 9              {
10                  if (number % scale < 10) { mychar[j++] = (char)(number % scale + '0'); }
11                  else { mychar[j++] = (char)(number % scale - 10 + 'A'); }
12                  number = number / scale;
13              } while (number / scale!=0);
14             for (int i = 1; i <= j; i++)
15             {
16                 mystr += mychar[j - i];
17             }
18             Console.WriteLine("{0}={1}", mynumber, mystr);
19         }

VB.NET:

Sub TestMath_5(number As Integer, scale As Integer)

        Dim mynumber As Integer = number
        Dim mystr As String = Nothing
        Dim mychar(100) As Char
        Dim i, j As Integer
        While (number >= scale)
            If (number Mod scale < 10) Then
                mychar(i) = ChrW(number Mod scale + AscW("0"))
            Else
                mychar(i) = ChrW(number Mod scale - 10 + AscW("A"))
            End If

            i += 1
            number = Math.Truncate(number / scale)

        End While

        If (number < scale) Then

            If (number Mod scale < 10) Then
                mychar(i) = ChrW(number Mod scale + AscW("0"))
            Else
                mychar(i) = ChrW(number Mod scale - 10 + AscW("A"))
            End If
        End If

        For j = 0 To i
            mystr += mychar(i - j)
        Next

        Console.WriteLine("{0}={1}", mynumber, mystr)

二、任意进制的数转换10进制数

基本思路：对对应加权位上的数*对应的加权值，然后全部加起来。

C#:

 1  static void TestMath_6(string number, int scale)
 2         {
 3             int length = number.Length;
 4             int num = 0;
 5             int gt = 0;
 6             for (int i = 0; i < length; i++)
 7             {
 8                 if (number[i] >= 'a')
 9                 {
10                     gt = number[i] - 'a' + 10;
11                 }
12                 else if (number[i] >= 'A')
13                 {
14                     gt = number[i] - 'A' + 10;
15                 }
16 
17                 //每个位置的数
18                 else if (number[i] >= '0')
19                 {
20                     gt = number[i] - '0';
21                 }
22                 num += gt * (int)(Math.Pow(scale, (length - i - 1)));
23             }
24             Console.WriteLine("{0}={1}", number, num);
25 
26         }

VB.NET:

 1 Sub TestMath_6(number As String, scale As Integer)
 2 
 3         Dim num As Integer = 0 '返回的数
 4         Dim gt As Integer = 0 '每个加权位上的值
 5         Dim length As Integer = number.Length
 6         For i = 0 To length - 1
 7             If (number(i) >= "a") Then
 8                 gt = CInt(AscW(number(i))) - AscW("a") + 10
 9             ElseIf (number(i) >= "A") Then
10                 gt = CInt(AscW(number(i))) - AscW("A") + 10
11             ElseIf (number(i) >= "0") Then
12                 gt = CInt(AscW(number(i))) - 48
13             End If
14 
15             num += gt * (CInt(scale ^ (length - i - 1)))
16         Next
17         Console.WriteLine("{0}={1}", number, num)
18     End Sub