package algs14;
import stdlib.*;

public class XPerformanceOfArrays {
  private double[] a;
  private int N;
  public XPerformanceOfArrays() {
    this.a = new double[1];
    this.N = 0;
  }
  private void resize(int capacity) {
    double[] temp = new double[capacity];
    for (int i = 0; i < N; i+=1) {
      if (SHOW) StdOut.format ("%02d ", i);
      temp[i] = a[i];
      ops += 1;
    }
    if (SHOW) StdOut.println();
    a = temp;
  }
  public void push(double item) {
    if (N == a.length) resize (1+N); //resize((int)Math.ceil (N*1.5));
    a[N] = item;
    N += 1;
    ops += 1;
  }
  
  private static long ops;
  private static boolean SHOW = true;
  public static void main(String[] args) {
    timeTrial(32);
    SHOW = false;
    
    int MIN = 256; 
    int MAX = 100_000_000;
    double prevTime = timeTrial(MIN);
    double prevOps = ops;
    double deltaSum = 0;
    int deltaNum = 0;
    for (int N = MIN*2; N<=MAX; N += N) {
      double time = timeTrial(N);
      StdOut.format ("Elapsed count f(%,13d): %,17d: %10.3f [%10.3f : %10.3f]\n", N, ops, ops / prevOps, time, time/prevTime);
      prevTime = time;
      deltaSum += ops/prevOps;
      deltaNum += 1;
      prevOps = ops;
    }
    StdOut.format ("Average delta: %.3f\n", deltaSum/deltaNum);
  }
  public static double timeTrial(int N) {
    ops = 0;
    Stopwatch s = new Stopwatch();
    XPerformanceOfArrays stack = new XPerformanceOfArrays();
    for (int j=0; j<N; j+=1) {
      stack.push (j);
    }
    return s.elapsedTime();
  }
}