public static int NumberOfPrimeUnder(int number)
{
int result = 0;
for (int i = 2; i <= number; i++)
{
if (FunctionsMath.IsPrime(i))
{
result++;
}
}
return(result);
}
public static List <int> GetPrimesBefore(int number)
{
List <int> result = new List <int>
{
2
};
for (int i = 3; i <= number; i = i + 2)
{
if (FunctionsMath.IsPrime(i))
{
result.Add(i);
}
}
return(result);
}
public static Dictionary <int, int> NumberOfPrimesByHundred(int number)
{
Dictionary <int, int> result = new Dictionary <int, int>();
for (int i = 2; i <= number; i++)
{
if (FunctionsMath.IsPrime(i))
{
int index = (Math.Abs(i / 100) + 1) * 100;
if (result.ContainsKey(index))
{
result[index]++;
}
else
{
result.Add(index, 1);
}
}
}
return(result);
}
public static bool IsTwinPrime(int number)
{
return(FunctionsMath.IsPrime(number) && FunctionsMath.IsPrime(number + 2));
}
private static void Main()
{
Action <string> display = Console.WriteLine;
Action <string> displayOnOneLine = Console.Write;
display("Demo to use the useful functions DLL");
int[] list = { 1, 2, 3, 1 };
bool result = StringFunc.HasDuplicate(list);
display("The array: {1, 2, 3, 1 } has duplicate: " + result);
display(string.Empty);
displayOnOneLine("Factorial 3 with lowerBound 2 is ");
displayOnOneLine(MathFunc.Factorial(3, 2).ToString());
display(string.Empty);
displayOnOneLine("IsNumeric of '4' ");
displayOnOneLine(StringFunc.IsNumeric("4").ToString());
char[] tmpNull = null;
// ReSharper disable once ExpressionIsAlwaysNull
string rdnString = StringFunc.GenerateRandomString(tmpNull);
display(string.Empty);
display("Generation of a random string: " + rdnString);
display(string.Empty);
display("Manifest of the DLL: " + StringFunc.Manifest());
display(string.Empty);
display("Generation of a 10 random filename strings: ");
for (int i = 0; i < 10; i++)
{
rdnString = StringFunc.GenerateRandomString(new[] { ' ' }, true, enumRnd.UpperLowerDigitSpecial, 8, true);
display("Random filename: " + rdnString);
}
string test = Path.GetRandomFileName();
display(string.Empty);
display("Generation of a 10 Path.GetRandomFileName: ");
for (int i = 0; i < 10; i++)
{
display("Random filename: " + Path.GetRandomFileName());
}
display("Listing all drives:");
List <DriveInfo> allDir = FileFunc.GetAllDrives(new[] { DriveType.CDRom, DriveType.Network,
DriveType.Removable });
foreach (var dirName in allDir)
{
display(dirName.ToString());
}
display("displaying all directories:");
var allfilesAndFolders = FileFunc.GetAllDirectories(@"C:\");
var count = 0;
foreach (var item in allfilesAndFolders)
{
display(item);
count++;
}
display(count + " directories were found");
display("");
display("Punctuation characters:");
display("Period: " + Punctuation.Period);
display("Backslash: " + Punctuation.Backslash);
display("Colon: " + Punctuation.Colon);
Livre dune = new Livre
{
Auteur = "Frank Herbert",
Prix = 20.00M,
Titre = "Les enfants de Dune"
};
// search for twin primes
display("Searching for twin primes:");
foreach (int twin in FunctionsPrimes.GetTwinPrimeBefore(500))
{
Console.Write($"{twin} ");
}
Stopwatch chrono2 = new Stopwatch();
chrono2.Start();
var allTwinPrimes = FunctionsPrimes.GetTwinPrimeBefore(int.MaxValue - 2);
chrono2.Stop();
TimeSpan ts2 = chrono2.Elapsed;
string elapsedTime2 = string.Format("{0:00}:{1:00}:{2:00}.{3:00}",
ts2.Hours, ts2.Minutes, ts2.Seconds,
ts2.Milliseconds / 10);
try
{
using (StreamWriter sw2 = new StreamWriter("twinPrimes.txt"))
{
sw2.WriteLine(string.Format("{0:00}:{1:00}:{2:00}.{3:00}", ts2.Hours, ts2.Minutes, ts2.Seconds, ts2.Milliseconds / 10));
sw2.WriteLine("RunTime with chrono: " + elapsedTime2);
foreach (int twin in allTwinPrimes)
{
sw2.WriteLine(twin);
}
}
}
catch (Exception)
{
display("There were an error while trying to write to a file all twin primes before int.max");
}
// calculating the time necessary to go through all numbers until int.max about billions
var startTime = DateTime.Now;
Stopwatch chrono = new Stopwatch();
chrono.Start();
for (int i = 0; i < int.MaxValue; i++)
{
}
var endTime = DateTime.Now;
chrono.Stop();
TimeSpan ts = chrono.Elapsed;
string elapsedTime = string.Format("{0:00}:{1:00}:{2:00}.{3:00}",
ts.Hours, ts.Minutes, ts.Seconds,
ts.Milliseconds / 10);
Console.WriteLine("RunTime " + elapsedTime);
using (StreamWriter sw = new StreamWriter("timeToIntMax.txt"))
{
sw.WriteLine($"start time is {startTime}");
sw.WriteLine($"End time is {endTime}");
sw.WriteLine(string.Format("{0:00}:{1:00}:{2:00}.{3:00}", ts.Hours, ts.Minutes, ts.Seconds, ts.Milliseconds / 10));
sw.WriteLine("RunTime with chrono: " + elapsedTime);
}
//for (int i = 0; i < FunctionsPrimes.GetTwinPrimeBefore(500).Count; i +=2)
//{
// Console.Write($"{twin} ");
//}
/* twin primes
* 2-3
* 11-13
* 17-19
* 41-43
* 71-73
* 101-103
* 107-109
* 197-199
* 227-229
* 281-283
* 311-313
* 431-433
* 461-463
* */
display("");
//display("primes:");
//for (int i = 3; i < 500; i = i + 2)
//{
// if (FunctionsMath.IsPrime(i))
// {
// Console.Write($"{i} ");
// }
//}
display("");
display("Press any key to exit:");
Console.ReadKey();
}