UVa - 10810 - Ultra-QuickSort

import java.io.BufferedInputStream;
import java.util.Scanner;

public class Main {
static long num = 0 ; 
public static void main (String args[] ){
Scanner scan =  new Scanner(new BufferedInputStream(System.in));
while(scan.hasNext()){
int n =  scan.nextInt();
if(n == 0 )
break ; 
num = 0 ; 
int data[] =  new int[n];
for(int  i = 0 ; i < n ; ++ i ){
data [i] =  scan.nextInt();

}
mergeSort(data , 0 , n - 1 );
System.out.println(num);
}

}

static void mergeSort(int array[] , int left , int right){
if( left  <  right ){
int center   = (left + right )  / 2 ; 
mergeSort(array , left , center );
mergeSort(array , left , center );
mergeSort(array , center+ 1 , right ); 
Merge(array , left ,center , right );
}


}

static void Merge (int array[] , int left  , int center , int right ){
int [] temp  =  new int[right - left + 1];
int  i = left ;
int j =  center + 1 ;
int k = 0 ;
while ( i <= center && j <= right ){
if (array[i]  > array [j])
{
temp[k++] = array[j++];
num += center - i + 1 ;
}else
{
temp[k++] = array[i++] ;
}
}
while ( i <= center )
temp[k++] = array[i++];

while (j <= right ){
temp[k++] = array [j++];
}

for(i = left , k = 0 ; i< right ; i++ , k++){
array[i] = temp[k];
}
}

}