Advertisement
simeon_petrov

34. Check Prime Number 100%

Dec 4th, 2017
267
0
Never
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
C# 0.82 KB | None | 0 0
  1. using System;
  2.  
  3.  
  4.    public class CheckPrimeNumber
  5.     {
  6.         static void Main()
  7.         {
  8.             long num1;
  9.             num1 = long.Parse(Console.ReadLine());
  10.  
  11.             if (IsPrime(num1))
  12.             {
  13.                 Console.WriteLine("Prime");
  14.             }
  15.             else
  16.             {
  17.                 Console.WriteLine("Not prime");
  18.             }
  19.         }
  20.  
  21.         public static bool IsPrime(long number)
  22.         {
  23.             if (number <= 1) return false;
  24.             if (number == 2) return true;
  25.             if (number % 2 == 0) return false;
  26.  
  27.             long boundary = (long)Math.Floor(Math.Sqrt(number));
  28.  
  29.             for (long i = 3; i <= boundary; i += 2)
  30.             {
  31.                 if (number % i == 0) return false;
  32.             }
  33.  
  34.             return true;
  35.         }
  36.       }
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement