import java.util.*; import java.util.stream.IntStream; public class Adjacent { static Set clones = new LinkedHashSet<>(); public static void main(String[] args) { int rows = 5; int columns = 5; char[][] chars = generateArray(rows, columns); int[] ints = calculateAdjacent(chars); printTable(chars, "Before removing clones"); printAdjacents(chars, ints); removeClones(chars); printTable(chars, "After removing clones"); printTable(replaceClones(chars), "After replacing clones"); } public static char[][] generateArray(int rows, int columns) { char[][] array = new char[rows][columns]; Random rn = new Random(); for (int r = 0; r < rows; r++) { for (int c = 0; c < columns; c++) { array[r][c] = (char) (rn.nextInt('Z' - 'A' + 1) + 'A'); } } return array; } public static int[] calculateAdjacent(char[][] chars) { int[][] indexes = {{-1, 1}, {0, 1}, {1, 0}, {1, 1}}; int[] count = new int['Z' - 'A' + 1]; for (int r = 0; r < chars.length; r++) { for (int c = 0; c < chars[0].length; c++) { for (int[] index : indexes) { int row = r + index[0]; int column = c + index[1]; if (isInRange(chars, row, column) && chars[r][c] == (chars[row][column])) { if (!clones.contains("" + row + column)) { count[chars[r][c] - 'A']++; } if (!clones.contains("" + r + c)) { count[chars[r][c] - 'A']++; } clones.add("" + r + c); clones.add("" + row + column); } } } } return count; } private static void printAdjacents(char[][] chars, int[] ints) { IntStream.rangeClosed(0, 'Z' - 'A') .filter(i -> ints[i] > 0) .mapToObj(i -> (char) (i + 'A') + " = " + (ints[i]) + " adjacent clones") .forEach(System.out::println); } private static boolean isInRange(char[][] strings, int row, int column) { return row >= 0 && row < strings.length && column >= 0 && column < strings[0].length; } public static void printTable(char[][] chars, String val) { StringBuilder sb = new StringBuilder("\n").append(val).append("\n"); for (int r = 0; r < chars.length; r++) { for (int c = 0; c < chars[0].length; c++) { sb.append(chars[r][c]).append(" "); } sb.append("\n"); } System.out.println(sb.toString()); } public static void removeClones(char[][] chars) { for (String clone : clones) { int r = Integer.parseInt(clone.charAt(0) + ""); int c = Integer.parseInt(clone.charAt(1) + ""); chars[r][c] = ' '; } } public static char[][] replaceClones(char[][] chars) { char[][] newChars = Arrays.copyOf(chars, chars.length); int[][] indexes = { {-1, -1}, {-1, 0}, {-1, 1}, {0, -1}, {0, 1}, {1, -1}, {1, 0}, {1, 1} }; List ch; for (String clone : clones) { int r = Integer.parseInt(clone.charAt(0) + ""); int c = Integer.parseInt(clone.charAt(1) + ""); ch = new LinkedList<>(); for (int[] index : indexes) { int row = r + index[0]; int col = c + index[1]; if (isInRange(newChars, row, col)) { if (newChars[row][col] != ' ') { ch.add(newChars[row][col]); } } } for (int i = 'A'; i <= 'Z'; i++) { if (!ch.contains((char) i)) { newChars[r][c] = (char) i; break; } } } return newChars; } }

Adjacent Clone Letters [Bonus]