Getting Factors of a Number

Question

I\'m trying to refactor this algorithm to make it faster. What would be the first refactoring here for speed?

public int GetHowManyFactors(int numberToCheck         


        

Answer 1

https://codility.com/demo/results/demoAAW2WH-MGF/

 public int solution(int n) {
      var counter = 0;          
      if (n == 1) return 1;
      counter = 2; //1 and itself      
      int sqrtPoint = (Int32)(Math.Truncate(Math.Sqrt(n)));
      for (int i = 2; i <= sqrtPoint; i++)
      {
        if (n % i == 0)
        {
          counter += 2; //  We found a pair of factors.         
        }       
      }
      // Check if our number is an exact square.
      if (sqrtPoint * sqrtPoint == n)
      {
        counter -=1;
      }

      return counter;
    }