Poj Solution 2291

http://poj.org/problem?id=2291

//* @author popop0p0popo
import java.util.*;
import java.io.*;

public class Main{
 public static void main(String[] args){
   Scanner scanner=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        int t=scanner.nextInt();
        int n,max;
        int[] r;
        for (int i=0;i< t ;i++ ){
            n=scanner.nextInt();
            r=new int[n];
            for (int j=0;j< n ;j++ ){
                r[j]=scanner.nextInt();
            }
            intSort(r,0,n-1);
            max=n*r[0];
            for (int j=1;j< n ;j++ ){
                if ((n-j)*r[j]>max){
                    max=(n-j)*r[j];
                }
            }
            System.out.println(max);
        }
    }

    public static void intSort(int[] number,int left,int right){
        if (left< right){
            int s=number[(left+right)/2];
            int i=left-1;
            int j=right+1;
            while (true){
                while (number[++i]< s);
                while (number[--j]>s);
                if (i>=j) break;
                swap(number,i,j);
            }
            intSort(number,left,i-1);
            intSort(number,j+1,right);
        }
    }

    public static void swap(int[] number,int i,int j) {
        int t;
        t=number[i];
        number[i]=number[j];
        number[j]=t;
    }
}