(URI) Acima da Diagonal Secundária - Solução

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

class Main  {
    static final int NUM = 12;
    static int total;

    public static void readMatrix(Scanner sc, float[][] matrix) {
        for (int i = 0; i < NUM; i++) {
            for (int j = 0; j < NUM; j++) {
                matrix[i][j] = sc.nextFloat();
            }
        }
    }
   
    public static float calcSum(float[][] matrix) {
        float sum = 0;
        int limit = NUM;
        total = 0;
       
        for (int i = 0; i < NUM; i++) {
            limit--;
            for (int j = 0; j < limit; j++) {
                sum += matrix[i][j];
                total++;
            }
        }
       
        return sum;
    }
   
    public static void printAnswer(String s, float sum) {
        if (s.equals("S")) {
            System.out.println(String.format("%.1f", sum));
        }
        else {
            System.out.println(String.format("%.1f", sum/total));
        }
    }
   
    public static void process() throws NumberFormatException, IOException {   
        Scanner sc = new Scanner(System.in);
       
        float[][] matrix = new float[NUM][NUM];

        String s = sc.next();
        readMatrix(sc, matrix);
       
        float sum = calcSum(matrix);
       
        printAnswer(s, sum);
                               
        return;
    }
   
    public static void main(String[] args) throws NumberFormatException, IOException {
        Main m = new Main();
        m.process();

        System.exit(0);
    }
}