1 /**
2 * Copyright (c) 2004-2011 QOS.ch
3 * All rights reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25 package org.slf4j.profiler;
26
27 import java.util.ArrayList;
28 import java.util.Arrays;
29
30 public class SortAndPruneComposites {
31
32 static String NESTED_PROFILER_NAME = "SORT_AND_PRUNE";
33
34 final int[] originalArray;
35 final int originalArrrayLength;
36
37 public SortAndPruneComposites(int[] randomArray) {
38 this.originalArray = randomArray;
39 this.originalArrrayLength = randomArray.length;
40
41 }
42
43 public int[] sortAndPruneComposites() {
44 // retrieve previously registered profiler named "SORT_AND_PRUNE"
45 ProfilerRegistry profilerRegistry = ProfilerRegistry.getThreadContextInstance();
46 Profiler sortProfiler = profilerRegistry.get(NESTED_PROFILER_NAME);
47
48 // start a new stopwatch called SORT
49 sortProfiler.start("SORT");
50 int[] sortedArray = sort();
51 // start a new stopwatch called PRUNE_COMPOSITES
52 sortProfiler.start("PRUNE_COMPOSITES");
53 int[] result = pruneComposites(sortedArray);
54
55 return result;
56 }
57
58 private int[] sort() {
59 int[] sortedArray = new int[originalArrrayLength];
60 System.arraycopy(originalArray, 0, sortedArray, 0, originalArrrayLength);
61 Arrays.sort(sortedArray);
62 return sortedArray;
63 }
64
65 int[] pruneComposites(int[] sortedArray) {
66 ArrayList<Integer> primesArray = new ArrayList<>();
67 for (int i = 0; i < originalArrrayLength; i++) {
68 int n = sortedArray[i];
69 if (isPrime(n)) {
70 primesArray.add(n);
71 }
72 }
73 int resultSize = primesArray.size();
74 int[] result = new int[resultSize];
75
76 for (int i = 0; i < resultSize; i++) {
77 result[i] = primesArray.get(i);
78 }
79 return result;
80 }
81
82 public boolean isPrime(int n) {
83 if (n < 2) {
84 return false;
85 }
86 if (n % 2 == 0) {
87 return false;
88 }
89 for (int i = 3; i * i <= n; i += 2) {
90 if (n % i == 0) {
91 return false;
92 }
93 }
94 return true;
95 }
96 }