package algs14;
import stdlib.*;
public class XCountingRecursion {
  /* testing an integer function */
  public static long f (long N) {
    if (N <= 1) {
      return 1;
    } else {
      long result = f(N-1) * N;     
      numOps = numOps + 1;
      return result;
    }
  }
//  public static String f (long N) {
//    if (N == 0) {
//      return "";
//    } else {
//      String result = "*" + f(N - 1);
//      numOps = numOps + result.length();
//      return result;
//    }
//  }
  private static long numOps;
  public static void main (String[] args) {
    long MIN = 4L; 
    long MAX = 5000L; // If too big, you may get a StackOverflowException
    Stopwatch sw = new Stopwatch ();
    numOps = 0;
    f(MIN);
    double prevCount = numOps;
    double prevTime = sw.elapsedTime ();
    for (long N = MIN*2; N <= MAX; N=N*2) {
      sw = new Stopwatch ();
      numOps = 0;
      f(N);
      long count = numOps; 
      double time = sw.elapsedTime ();
      StdOut.format ("Elapsed count f(%,13d): %,17d: %10.3f [%10.3f : %10.3f]\n", N, count, count / prevCount, time, time/prevTime);
      //StdOut.format ("Elapsed count f(%,13d): %,17d: %10.3f\n", N, count, count / prevCount);
      prevCount = count;
      prevTime = time;
    }
  }
}