Alguém entendeu a lógica do segundo método da classe “GameHelper” ? Poderia (se não for pedir demais rs) reescrevê-lo de forma a que ele seja entendível para iniciantes?
Muito obrigada! 
Classe GameHelper:
package sinkADotCom;
import java.io.*;
import java.util.*;
public class GameHelper {
private static final String alphabet = "abcdefg";
private int gridLength = 7;
private int gridSize = 49;
private int [] grid = new int[gridSize];
private int comCount = 0;
public String getUserInput(String prompt){
String inputLine = null;
System.out.print(prompt + " ");
try{
BufferedReader is = new BufferedReader(new InputStreamReader(System.in));
inputLine = is.readLine();
if(inputLine.length() == 0){
return null;
}
}catch(IOException e){
System.out.println("IOException: " + e);
}
return inputLine.toLowerCase();
}
public ArrayList<String> placeDotCom (int comSize){
ArrayList<String> alphaCells = new ArrayList<String>();
String [] alphaCoords = new String [comSize];
String temp = null;
int [] coords = new int [comSize];
int attempts = 0;
boolean success = false;
int location = 0;
comCount++;
int incr = 1;
if((comCount % 2) == 1){ //Retorna o resto da divisão de comCount por 2
incr = gridLength;
}
while(!success & attempts++ < 200){
location = (int)(Math.random() * gridSize);
//System.out.print("try " + location);
int x = 0;
success = true;
while(success && x < comSize){
if(grid[location] == 0){
coords[x++] = location;
location += incr;
if(location >= gridSize){
success = false;
}
if(x > 0 && (location % gridLength == 0)){
success = false;
}
}else{
//System.out.print("used " + location);
success = false;
}
}
}
int x = 0;
int row = 0;
int column = 0;
//System.out.println("\n");
while (x < comSize){
grid[coords[x]] = 1;
row = (int)(coords[x] / gridLength);
column = coords[x] % gridLength;
temp = String.valueOf(alphabet.charAt(column));
alphaCells.add(temp.concat(Integer.toString(row)));
x++;
//System.out.print("coord " + x + " = " + alphaCells.get(x-1));
}
//System.out.println("\n");
return alphaCells;
}
}