Prime Numbers and Fibonacci

Question

Good day guysplease how can i write a console application on c# that will read in positive integer value and determine if the number is a prime number and if the number is a fibonacci number.Thanks alot.

Vulpes · Answer

Try this: using System; class Program { static void Main() { int n ; while(true) { Console.Write(Enter a positive integer or 0 to finish : ); int.TryParse(Console.ReadLine() out n); if (n == 0) return; if (n { Console.WriteLine(Negative integers not allowed!); continue; } if(IsPrime(n)) { Console.WriteLine({0} is a prime number n); } else { Console.WriteLine({0} is not a prime number n); } if(IsFibonacci(n)) { Console.WriteLine({0} is a Fibonacci number n); } else { Console.WriteLine({0} is not a Fibonacci number n); } Console.WriteLine(); } } static bool IsPrime(int x) { if (x for (int i = 2; i { if ((x % i) == 0) { return false; } } return true; } static bool IsFibonacci(int x) { if (x == 1 ) return true; int first = 1; int second = 1; int third = 2; while(third { if (third == x) return true; first = second; second = third; third = first + second; } return false; } }