程序的关键在于你需要有一种迭代 SIN 中每个整数的方法。
由于最简单的方法是将整数转换为字符串进行操作,然后再将其转换回整数进行加法/乘法操作,因此我采用了以下方法:
程序:
public class Program
{
static void Main(string[] args)
{
int sn = 123456782;
int[] Digits;
int AddedResult = 0;
string s = sn.ToString();
string sa = s.Substring(s.Length - 1, 1);
int checkDigit = Convert.ToInt32(sn.ToString().Substring(s.Length - 1, 1));
if (IsValidLength(sn))
{
sn = RemoveLastDigit(sn);
Digits = ExtractEvenDigits(sn);
Digits = DoubleDigits(Digits);
AddedResult = AddedEvenDigits(Digits);
AddedResult += AddOddDigits(sn);
if (IsValidSN(AddedResult, checkDigit))
{
Console.WriteLine("The number is valid");
}
else
{
Console.WriteLine("The Number is not valid");
}
}
else
{
Console.WriteLine("NotValidLength");
}
Console.Read();
}
public static bool IsValidSN(int AddedResult, int checkDigit)
{
return ((AddedResult % 10 == 0 && checkDigit == 0) || IsValidDifference(AddedResult, checkDigit));
}
public static bool IsValidDifference(int AddedResult, int checkDigit)
{
int nextHighestTens = AddedResult;
while (nextHighestTens % 10 != 0)
{
nextHighestTens++;
}
return ((nextHighestTens - AddedResult) == checkDigit);
}
public static int AddOddDigits(int sn)
{
string s = sn.ToString();
int i = 1;
int addedResult = 0;
foreach (char c in s)
{
if (i % 2 != 0)
{
addedResult += Convert.ToInt32(c.ToString());
}
i++;
}
return addedResult;
}
public static int AddedEvenDigits(int[] Digits)
{
int addedEvenDigits = 0;
string s = "";
for (int i = 0; i < Digits.Length; i++)
{
s += Digits[i].ToString();
}
for (int i = 0; i < s.Length; i++)
{
addedEvenDigits += Convert.ToInt32(s[i].ToString());
}
return addedEvenDigits;
}
public static int[] DoubleDigits(int[] Digits)
{
int[] doubledDigits = new int[Digits.Count()];
for (int i = 0; i < Digits.Length; i++)
{
doubledDigits[i] = Digits[i] * 2;
}
return doubledDigits;
}
public static int[] ExtractEvenDigits(int sn)
{
int[] EvenDigits = new int[4];
string s = sn.ToString();
int j = 0;
for (int i = 1; i < s.Length; i += 2)
{
EvenDigits[j] = Convert.ToInt32(s[i].ToString());
j++;
}
return EvenDigits;
}
public static int RemoveLastDigit(int sn)
{
string s = sn.ToString();
return Convert.ToInt32(s.Substring(0, s.Count() - 1));
}
public static bool IsValidLength(int sn)
{
return (sn > 9999999 && sn < 1000000000);
}
}
我大约花了20分钟写了这个,所以它并不值得提交。我计划将其作为练习进行改进,并编写了一些单元测试(我计划将其改进)。
[TestFixture]
public class SINTests
{
private int SinNumber = 123456782;
[Test]
public void TestValidNumber()
{
Assert.IsTrue(Program.IsValidLength(SinNumber));
}
[Test]
public void TestRemoveLastDigit()
{
Assert.AreEqual(12345678, Program.RemoveLastDigit(SinNumber));
}
[Test]
public void TestExtractEvenDigit()
{
int sn = 12345678;
int[] array = new int[] { 2,4,6,8 };
Assert.AreEqual(array, Program.ExtractEvenDigits(sn));
}
[Test]
public void TestAddOddDigits()
{
int sn = 12345678;
int result = 1 + 3 + 5 + 7;
Assert.AreEqual(result, Program.AddOddDigits(sn));
}
[Test]
public void TestDoubleEvenDigits()
{
int sn = 12345678;
int[] original = new int[] { 2, 4, 6, 8 };
int[] array = new int[] { 4, 8, 12, 16 };
Assert.AreEqual(array, Program.DoubleDigits(original));
}
[Test]
public void TestOddDigits()
{
int sn = 12345678;
Assert.AreEqual(16, Program.AddOddDigits(sn));
}
}
由于字符串可以被看作是字符数组1,因此对字符串进行操作的方法也需要意识到将字符转换为整数与将字符串转换为整数是不同的。例如:
Char c = '2';
int cInt = Convert.ToInt32(c); // returns 50
string s = c.ToString();
int sInt = Convert.ToInt32(s) //returns 2;
1从技术上讲,在C#中,字符串不是字符数组(尽管在C和C++中是),但由于可以通过索引器访问字符串的组件,因此它可以像字符数组一样处理。