(UVA) Add All - Solution

Link to the problem: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=1895

The solution below used a Priority Queue to solve this problem because the best solution is always to sum the two smallest numbers.


import java.io.*;
import java.util.*;

class Main {
    public void process() throws NumberFormatException, IOException {
        Scanner sc = new Scanner(System.in);
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int numNumbers = sc.nextInt();
        while (numNumbers != 0) {
            Queue<Integer> queue = new PriorityQueue<>();
            for (int i = 0; i < numNumbers; i++) {
                queue.add(sc.nextInt());
            }

            int lastSum = queue.poll()+queue.poll();
            queue.add(lastSum);
            int sumCost = lastSum;
            for (int i = 2; i < numNumbers; i++) {
                lastSum = queue.poll()+queue.poll();
                queue.add(lastSum);
                sumCost += lastSum;
            }
           
            bw.write(sumCost+"\n");
           
            numNumbers = sc.nextInt();
        }
                                              
        bw.flush();
        bw.close();
       
        return;
    }
   
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();
       
        System.exit(0);
    }
}