/*B - 广搜/深搜 基础Time Limit:1000MS     Memory Limit:30000KB     64bit IO Format:%I64d & %I64uSubmit StatusDescriptionThere 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. InputThe 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. OutputFor each data set, your program should output a line which contains the number of tiles he can reach from the initial tile (including itself).Sample Input6 9....#......#..............................#@...#.#..#.11 9.#..........#.#######..#.#.....#..#.#.###.#..#.#..@#.#..#.#####.#..#.......#..#########............11 6..#..#..#....#..#..#....#..#..###..#..#..#@...#..#..#....#..#..#..7 7..#.#....#.#..###.###...@...###.###..#.#....#.#..0 0Sample Output4559613By Grant Yuan2014.7.12*/#include
     
      #include
      
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        #include
        
         #include
         
          using namespace std;bool flag[21][21];char a[21][21];int n,m;int s1,f1;typedef struct{ int x; int y;}node;int next[4][2]={1,0,0,1,-1,0,0,-1};int sum;queue
          
           q;bool can(int cc,int dd){ if(cc>=0&&cc
           
            =0&&dd
            
             >n>>m; if(n==0&&m==0) break; for(int i=0;i