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  1. import java.util.*;
  2.  
  3. public class Main {
  4.  
  5.    public static void main(String[] args) {
  6.  
  7.      int[] arr = {9,8,7,6,-5,-4,-31,2,1};
  8.  
  9.      System.out.println("Input:");
  10.      display(arr);
  11.      mergesort(arr);
  12.      System.out.println("\nOutput:");
  13.      display(arr);
  14.      System.out.println("\n");
  15.    }
  16.  
  17.    public static void display(int arr[]) {
  18.  
  19.           for(int value: arr) {
  20.  
  21.               System.out.print(value + " ");
  22.           }
  23.    }
  24.  
  25.    public static void mergesort(int[] arr) {
  26.           divideEtImpera(0,arr.length-1,arr);
  27.    }
  28.  
  29.    public static void divideEtImpera(int lo, int hi, int arr[]) {
  30.           if(lo == hi) return;
  31.           int middle = (lo+hi)>>1;
  32.           divideEtImpera(lo,middle, arr);
  33.           divideEtImpera(middle+1,hi,arr);
  34.           merge(lo,middle,hi,arr);
  35.    }
  36.  
  37.    public static void merge(int lo, int m, int hi, int[] vec) {
  38.          int i=lo, j=m+1, k = 0;
  39.          int aux[] = new int[hi-lo+1];
  40.          while(i<=m && j<=hi) {
  41.              if(vec[i]<vec[j]) aux[k++] = vec[i++];
  42.                      else aux[k++] = vec[j++];
  43.          }
  44.          while(i<=m) aux[k++] = vec[i++];
  45.          while(j<=hi) aux[k++] = vec[j++];
  46.          k = 0;
  47.          for(int index=lo;index<=hi;index++) vec[index] = aux[k++];
  48.    }
  49. }
  50.  
Success #stdin #stdout 0.15s 53620KB
comments (?)
stdin 
Standard input is empty
stdout 
Input:
9 8 7 6 -5 -4 -31 2 1 
Output:
-31 -5 -4 1 2 6 7 8 9
https://ideone.com/hF3pbh
Merge Sort
language:
Java (HotSpot 12)
created:
1 year ago
visibility:
secret

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