361. Bomb Enemy

    /*
     * 361. Bomb Enemy 
     * 2016-7-15 by Mingyang
     */
       public int maxKilledEnemies(char[][] grid) {
            if (grid == null || grid.length == 0 || grid[0].length == 0) {
                return 0;
            }
            int ret = 0;
            int row = grid.length;
            int col = grid[0].length;
            int rowCache = 0;
            int[] colCache = new int[col];
            for (int i = 0;i < row; i++) {
                for (int j = 0; j < col; j++) {
                    if (j == 0 || grid[i][j-1] == 'W') {
                        rowCache = 0;
                        for (int k = j; k < col && grid[i][k] != 'W'; k++) {
                            rowCache += grid[i][k] == 'E' ? 1 : 0;
                        }
                    }
                    if (i == 0 || grid[i-1][j] == 'W') {
                        colCache[j] = 0;
                        for (int k = i;k < row && grid[k][j] != 'W'; k++) {
                            colCache[j] += grid[k][j] == 'E' ? 1 :0;
                        }
                    }
                    if (grid[i][j] == '0') {
                        ret = Math.max(ret, rowCache + colCache[j]);
                    }
                }
            }
            return ret;
        }