(UVA) Maximum Sub-sequence Product - Solution

Link to the problem: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=728

The solution below used Dynamic Programming to solve this problem. Moreover, once we would be handling very large numbers, it was necessary to use BigInteger class instead of int/long types.


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

class Main {
    public void process() throws NumberFormatException, IOException {
        Scanner sc = new Scanner(System.in);
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
       
        while (sc.hasNext()) {
            BigInteger max = new BigInteger("-1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000");

            int numNumbers = 0;
            int number = sc.nextInt();
            ArrayList<Integer> numbers = new ArrayList<>();
            while (number != -999999) {
                numbers.add(number);
                max = max.max(new BigInteger(String.valueOf(number)));
                numNumbers++;
               
                number = sc.nextInt();
            }
           
            BigInteger[] product = new BigInteger[numNumbers+1];
            product[0] = BigInteger.ONE;
            for (int i = 1; i <= numNumbers; i++) {
                product[i] = product[i-1].multiply(new BigInteger(String.valueOf(numbers.get(i-1))));
                max = max.max(product[i]);
            }
           
            for (int i = numNumbers; i >= 1; i--) {
                for (int j = i-1; j >= 1; j--) {
                    if (product[j].equals(BigInteger.ZERO)) {
                        max = max.max(BigInteger.ZERO);
                        continue;
                    }
                    max = max.max(product[i].divide(product[j]));
                }
            }
           
            bw.write(max+"\n");
        }
               
        bw.flush();
        bw.close();
       
        return;
    }
   
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();
       
        System.exit(0);
    }
}