不使用convert.to()方法，如何用八进制表示十进制负数？
public static string GetOctal(int number)
{
int base = 8;
}
例如：
-3（基数10）=37777777775（基数8）
但是我应该用什么算法得到这个结果呢？
这些是我的任务的测试用例：
[TestCase(-3, 8, ExpectedResult = "37777777775")]
[TestCase(-127, 8, ExpectedResult = "37777777601")]
[TestCase(-675432, 8, ExpectedResult = "37775330630")]
[TestCase(-1908345, 8, ExpectedResult = "37770560607")]
[TestCase(int.MinValue, 8, ExpectedResult = "20000000000")]
[TestCase(-3, 16, ExpectedResult = "FFFFFFFD")]
[TestCase(-127, 16, ExpectedResult = "FFFFFF81")]
[TestCase(-675432, 16, ExpectedResult = "FFF5B198")]
[TestCase(-1908345, 16, ExpectedResult = "FFE2E187")]
[TestCase(int.MinValue, 16, ExpectedResult = "80000000")]
[TestCase(1908345, 10, ExpectedResult = "1908345")]
[TestCase(int.MaxValue, 10, ExpectedResult = "2147483647")]
public string GetRadix_Tests(int number, int radix) => number.GetRadix(radix);
您始终可以在此处找到source.dot.NET中的Convert类的源代码，并遵循Parsenumber的IntToString方法：
public static string IntToString(int n, int radix, int width, char paddingChar, int flags)
{
Span<char> buffer = stackalloc char[66]; // Longest possible string length for an integer in binary notation with prefix
if (radix < MinRadix || radix > MaxRadix)
throw new ArgumentException(SR.Arg_InvalidBase, nameof(radix));
// If the number is negative, make it positive and remember the sign.
// If the number is MIN_VALUE, this will still be negative, so we'll have to
// special case this later.
bool isNegative = false;
uint l;
if (n < 0)
{
isNegative = true;
(...)
