Codingame : ASCII Art Solution

Solution.java

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

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/
class Solution {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int L = in.nextInt();
        in.nextLine();
        int H = in.nextInt();
        in.nextLine();
        String T = in.nextLine();
        List<String> ascii = new ArrayList<String>();
        int group = 0;
        
        for (int i = 0; i < H; i++) {
            String ROW = in.nextLine();
            int beginIndex = 0;
            int endIndex = L - 1;
             group = ROW.length() / L;
            for (int j = 0; j < group; j++) {
               //System.err.println("Tour: " + j + " group: " + group + " beginIndex: " + beginIndex + " endIndex: " + endIndex);
               ascii.add(ROW.substring(beginIndex, endIndex+1));
               beginIndex = endIndex + 1;
               endIndex = beginIndex + (L - 1);
               //System.err.println(ascii.get(j).length());
            }
        }
        
        char[] cArray = "ABCDEFGHIJKLMNOPQRSTUVWXYZ?".toCharArray();
        List<Character> letters = new ArrayList<Character>();
        for(char c : cArray) {
            letters.add(c);
        }
        T = T.toUpperCase();
        char[] ch = T.toCharArray();
        List<Integer> indexes = new ArrayList<Integer>();
        for (char c : ch) {
            if (!letters.contains(c)) {
                indexes.add(26);
                //Solution.printSolution(26, H, ascii, group);
            }
            else {
                indexes.add(letters.indexOf(c));
               
            }
        }
        Solution.printSolution(indexes, H, ascii, group);
    }
    
    private static void printSolution(List<Integer> indexes, int charHigth, List<String> ascii, int group) {
        List<Integer> pointers = indexes;
        int pointer = 0;
        for (int i = 0; i < charHigth; i++) {
            StringBuilder answer = new StringBuilder();
            for (int j = 0; j < pointers.size(); j++) {
                int index = pointers.get(j);
                index += pointer;
                answer.append(ascii.get(index));
            }
            pointer = pointer + group;
            System.out.println(answer.toString()); 
        }
    }
}