fork download
copy 
  1. import java.util.ArrayList;
  2. import java.util.Random;
  3.  
  4. class MergeSort {
  5.     public static void main(String[] args) {
  6.         Random r = new Random();
  7.         ArrayList<Integer> numbers = new ArrayList<Integer>();
  8.         for (int i = 1; i <= 15; i++) {
  9.             numbers.add(r.nextInt(100));
  10.         }
  11.         numbers = mergeSort(numbers);
  12.         System.out.println(numbers);
  13.     }
  14.  
  15.     public static ArrayList<Integer> mergeSort(ArrayList<Integer> m) {
  16.         if (m.size() <= 1) {
  17.             return m;
  18.         }
  19.         ArrayList<Integer> left = new ArrayList<Integer>();
  20.         ArrayList<Integer> right = new ArrayList<Integer>();
  21.         for (int i = 0; i < m.size(); i++) {
  22.             if (i < (m.size()) / 2)
  23.                 left.add(m.get(i));
  24.             else {
  25.                 right.add(m.get(i));
  26.             }
  27.         }
  28.         left = mergeSort(left);
  29.         right = mergeSort(right);
  30.         return merge(left, right);
  31.     }
  32.  
  33.     private static ArrayList<Integer> merge(ArrayList<Integer> l, ArrayList<Integer> r) {
  34.         ArrayList<Integer> result = new ArrayList<Integer>();
  35.         while (l.size() > 0 && r.size() > 0) {
  36.             if (l.get(0) <= r.get(0)) {
  37.                 result.add(l.get(0));
  38.                 l.remove(0);
  39.             } else {
  40.                 result.add(r.get(0));
  41.                 r.remove(0);
  42.             }
  43.         }
  44.         while (l.size() > 0) {
  45.             result.add(l.get(0));
  46.             l.remove(0);
  47.         }
  48.         while (r.size() > 0) {
  49.             result.add(r.get(0));
  50.             r.remove(0);
  51.         }
  52.         return result;
  53.     }
  54. }
Success #stdin #stdout 0.06s 32560KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
[3, 13, 20, 22, 40, 45, 51, 59, 63, 64, 72, 76, 85, 91, 98]
https://ideone.com/wvamvc
language:
Java (HotSpot 12)
created:
3 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!