• [1081] Red and Black

  • 时间限制: 1000 ms 内存限制: 65535 K
  • 问题描述
  • There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only on black tiles.

    Write a program to count the number of black tiles which he can reach by repeating the moves described above.
  • 输入
  • The input consists of multiple data sets. A data set starts with a line containing two positive integers W and H; W and H are the numbers of tiles in the x- and y- directions, respectively. W and H are not more than 20.

    There are H more lines in the data set, each of which includes W characters. Each character represents the color of a tile as follows.

    '.' - a black tile
    '#' - a red tile
    '@' - a man on a black tile(appears exactly once in a data set)
    The end of the input is indicated by a line consisting of two zeros.
  • 输出
  • For each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).
  • 样例输入
  • 6 9
    ....#.
    .....#
    ......
    ......
    ......
    ......
    ......
    #@...#
    .#..#.
    11 9
    .#.........
    .#.#######.
    .#.#.....#.
    .#.#.###.#.
    .#.#..@#.#.
    .#.#####.#.
    .#.......#.
    .#########.
    ...........
    11 6
    ..#..#..#..
    ..#..#..#..
    ..#..#..###
    ..#..#..#@.
    ..#..#..#..
    ..#..#..#..
    7 7
    ..#.#..
    ..#.#..
    ###.###
    ...@...
    ###.###
    ..#.#..
    ..#.#..
    0 0
  • 样例输出
  • 45
    59
    6
    13
  • 提示
  • 来源
  • POJ / Japan 2004 Domestic
  • 操作

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