(original) (raw)

import java.util.Random; import java.math.BigInteger; public enum ArrayBuilder { // These seven are from Tim's paper (listsort.txt) RANDOM_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = rnd.nextInt(); return result; } }, DESCENDING_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = len - i; return result; } }, ASCENDING_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = i; return result; } }, ASCENDING_3_RND_EXCH_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = i; for (int i = 0; i < 3; i++) swap(result, rnd.nextInt(result.length), rnd.nextInt(result.length)); return result; } }, ASCENDING_10_RND_AT_END_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; int endStart = len - 10; for (int i = 0; i < endStart; i++) result[i] = i; for (int i = endStart; i < len; i++) result[i] = rnd.nextInt(endStart + 10); return result; } }, ALL_EQUAL_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = 666; return result; } }, DUPS_GALORE_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = rnd.nextInt(4); return result; } }, RANDOM_WITH_DUPS_INT { public Object[] build(int len) { Integer[] result = new Integer[len]; for (int i = 0; i < len; i++) result[i] = rnd.nextInt(len); return result; } }, PSEUDO_ASCENDING_STRING { public String[] build(int len) { String[] result = new String[len]; for (int i = 0; i < len; i++) result[i] = Integer.toString(i); return result; } }, RANDOM_BIGINT { public BigInteger[] build(int len) { BigInteger[] result = new BigInteger[len]; for (int i = 0; i < len; i++) result[i] = HUGE.add(BigInteger.valueOf(rnd.nextInt(len))); return result; } }; public abstract Object[] build(int len); public void resetRandom() { rnd = new Random(666); } private static Random rnd = new Random(666); private static void swap(Object[] a, int i, int j) { Object t = a[i]; a[i] = a[j]; a[j] = t; } private static BigInteger HUGE = BigInteger.ONE.shiftLeft(100); }