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/*
* This benchmark has been ported from "The Computer Language Benchmarks Game" suite and slightly
* modified to fit the benchmarking framework.
*
* The original file:
* https://benchmarksgame-team.pages.debian.net/benchmarksgame/program/pidigits-java-1.html
*
* The Computer Language Benchmarks Game
* https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
*
* contributed by Isaac Gouy
*
* LICENSE: 3-Clause BSD
* https://benchmarksgame-team.pages.debian.net/benchmarksgame/license.html
*/
/*
* Description: Streaming arbitrary-precision arithmetic.
* Main Focus: TODO
*
*/
package benchmarks.benchmarksgame;
import java.math.BigInteger;
public class pidigits {
static final int L = 10;
private static final int PREDEFINED_N_DIGITS = 27;
public static void old_main() {
int n = PREDEFINED_N_DIGITS;
int j = 0;
PiDigitSpigot digits = new PiDigitSpigot();
while (n > 0) {
if (n >= L) {
for (int i = 0; i < L; i++) digits.next();
j += L;
} else {
for (int i = 0; i < n; i++) digits.next();
j += n;
}
n -= L;
}
}
public void timePidigits(int iters) {
for (int j = 0; j < iters; j++) {
old_main();
}
}
public boolean verifyPidigits() {
PiDigitSpigot digits = new PiDigitSpigot();
for (int i = 0; i < PREDEFINED_N_DIGITS; ++i) {
digits.next();
}
int expected = 3;
int found = digits.next();
if (expected != found) {
System.out.println("ERROR: Expected " + expected + " but found " + found);
return false;
}
return true;
}
public static void main(String[] args) {
int rc = 0;
pidigits obj = new pidigits();
final long before = System.currentTimeMillis();
obj.timePidigits(100);
final long after = System.currentTimeMillis();
if (!obj.verifyPidigits()) {
rc++;
}
System.out.println("benchmarks/benchmarksgame/pidigits: " + (after - before));
System.exit(rc);
}
}
// CHECKSTYLE.OFF: .*
class PiDigitSpigot {
Transformation z, x, inverse;
public PiDigitSpigot() {
z = new Transformation(1, 0, 0, 1);
x = new Transformation(0, 0, 0, 0);
inverse = new Transformation(0, 0, 0, 0);
}
public int next() {
int y = digit();
if (isSafe(y)) {
z = produce(y);
return y;
} else {
z = consume(x.next());
return next();
}
}
public int digit() {
return z.extract(3);
}
public boolean isSafe(int digit) {
return digit == z.extract(4);
}
public Transformation produce(int i) {
return (inverse.qrst(10, -10 * i, 0, 1)).compose(z);
}
public Transformation consume(Transformation a) {
return z.compose(a);
}
}
class Transformation {
BigInteger q, r, s, t;
int k;
public Transformation(int q, int r, int s, int t) {
this.q = BigInteger.valueOf(q);
this.r = BigInteger.valueOf(r);
this.s = BigInteger.valueOf(s);
this.t = BigInteger.valueOf(t);
k = 0;
}
public Transformation(BigInteger q, BigInteger r, BigInteger s, BigInteger t) {
this.q = q;
this.r = r;
this.s = s;
this.t = t;
k = 0;
}
public Transformation next() {
k++;
q = BigInteger.valueOf(k);
r = BigInteger.valueOf(4 * k + 2);
s = BigInteger.valueOf(0);
t = BigInteger.valueOf(2 * k + 1);
return this;
}
public int extract(int j) {
BigInteger bigj = BigInteger.valueOf(j);
BigInteger numerator = (q.multiply(bigj)).add(r);
BigInteger denominator = (s.multiply(bigj)).add(t);
return (numerator.divide(denominator)).intValue();
}
public Transformation qrst(int q, int r, int s, int t) {
this.q = BigInteger.valueOf(q);
this.r = BigInteger.valueOf(r);
this.s = BigInteger.valueOf(s);
this.t = BigInteger.valueOf(t);
k = 0;
return this;
}
public Transformation compose(Transformation a) {
return new Transformation(
q.multiply(a.q),
(q.multiply(a.r)).add((r.multiply(a.t))),
(s.multiply(a.q)).add((t.multiply(a.s))),
(s.multiply(a.r)).add((t.multiply(a.t))));
}
}
// CHECKSTYLE.ON: .*
|
