class Solution {

    public int[][] candyCrush(int[][] board) {

        int r = board.length, c = board[0].length;

        boolean crush = false;

        for (int i = 0; i < r; i++) {

            for (int j = 0; j < c; j++) {

                // check horizontal line

                int v = Math.abs(board[i][j]);

                if (v == 0) continue;

                if (j + 2 < c && v == Math.abs(board[i][j + 1]) && v == Math.abs(board[i][j + 2])) {

                    crush = true;

                    board[i][j] = board[i][j + 1] = board[i][j + 2] = -v;

                }

                // check vertical line

                if (i + 2 < r && v == Math.abs(board[i + 1][j]) && v == Math.abs(board[i + 2][j])) {

                    crush = true;

                    board[i][j] = board[i + 1][j] = board[i + 2][j] = -v;

                }

            }

        }

        // crush candy

        for (int j = 0; j < c; j++) {

            int id = r - 1;

            for (int i = r - 1; i >= 0; i--) {

                if (board[i][j] > 0) {

                    board[id--][j] = board[i][j];

                }

            }

            while (id >= 0) board[id--][j] = 0;

        }

        return crush ? candyCrush(board) : board;

    }

}