Solution.java

class Solution {
    public int[] findPattern(int[][] board, String[] pattern) {
        int m = board.length, n = board[0].length;
        int r = pattern.length, c = pattern[0].length();
        for (int i = 0; i < m - r + 1; ++i) {
            for (int j = 0; j < n - c + 1; ++j) {
                if (check(board, pattern, i, j)) {
                    return new int[] {i, j};
                }
            }
        }
        return new int[] {-1, -1};
    }

    private boolean check(int[][] board, String[] pattern, int i, int j) {
        int[] d1 = new int[26];
        int[] d2 = new int[10];
        Arrays.fill(d1, -1);
        Arrays.fill(d2, -1);
        for (int a = 0; a < pattern.length; ++a) {
            for (int b = 0; b < pattern[0].length(); ++b) {
                int x = i + a, y = j + b;
                if (Character.isDigit(pattern[a].charAt(b))) {
                    int v = pattern[a].charAt(b) - '0';
                    if (v != board[x][y]) {
                        return false;
                    }
                } else {
                    int v = pattern[a].charAt(b) - 'a';
                    if (d1[v] != -1 && d1[v] != board[x][y]) {
                        return false;
                    }
                    if (d2[board[x][y]] != -1 && d2[board[x][y]] != v) {
                        return false;
                    }
                    d1[v] = board[x][y];
                    d2[board[x][y]] = v;
                }
            }
        }
        return true;
    }
}