String to Integer (atoi)

Solution.cs

public class Solution {
    public int MyAtoi(string s) {
      sbyte sign = 1;
      int runningNumber = 0;
      bool isReadNumber = false;
      bool isOverflow = false;
      
      for(int i = 0; i < s.Length; i++)
      {
        if(Char.IsWhiteSpace(s[i]) && !isReadNumber) continue;
        else if(s[i] == '-' && !isReadNumber)
        {
          sign = -1;
          isReadNumber = true;
        }
        else if(s[i] == '+' && !isReadNumber)
        {
          isReadNumber = true;
        }
        else if(Char.IsNumber(s[i]))
        {
          isReadNumber = true;
          int currentInteger = (int)Char.GetNumericValue(s[i]);
          long newSum = ((runningNumber * 10) + currentInteger);
          if((newSum - currentInteger)/10 == runningNumber)
            runningNumber = (int)newSum;
          else
          {
            return sign == -1 ? Int32.MinValue: Int32.MaxValue;
          }
        }
        else break;
      }
      
      
      return runningNumber * sign;
    }
}