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package ds1.student.orderofgrowth;
import stdlib.*;
public class CountingStrings {
// Test variants that resize additively or multiplicatively
// int capacity = 1 + a.length;
// int capacity = 2 * a.length;
// int capacity = (int)Math.ceil(1.5 * a.length);
private static char[] resize (char[] a) {
int capacity = 2 * a.length;
char[] result = new char[capacity];
for (int i = 0; i < a.length; i = i + 1) {
result[i] = a[i];
numOps = numOps + 1;
}
return result;
}
// f creates a string of length N, counting the total size of all strings created
public static String f (long N) {
char[] a = new char[1];
for (int i = 0; i < N; i = i + 1) {
if (i >= a.length)
a = resize(a);
a[i] = '*';
numOps = numOps + 1;
}
return String.valueOf(a); // creates a string in linear time
}
private static long numOps;
public static void main (String[] args) {
long MIN = 500L;
long MAX = 3200000L;
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;
}
}
}
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