Red and Black
Description
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.
Write a program to count the number of black tiles which he can reach by repeating the moves described above.
Input
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)
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)
Output
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).
Sample Input
6 9 ....#. .....# ...... ...... ...... ...... ...... #@...# .#..#. 11 9 .#......... .#.#######. .#.#.....#. .#.#.###.#. .#.#..@#.#. .#.#####.#. .#.......#. .#########. ........... 11 6 ..#..#..#.. ..#..#..#.. ..#..#..### ..#..#..#@. ..#..#..#.. ..#..#..#.. 7 7 ..#.#.. ..#.#.. ###.### ...@... ###.### ..#.#.. ..#.#.. 0 0
Sample Output
45 59 6 13
1 #include<cstdio> 2 #include<cstring> 3 char a[30][30]; 4 bool b[30][30]; 5 int dx[4]={0,1,-1,0}; 6 int dy[4]={1,0,0,-1}; 7 int ans,m,n,x,y; 8 void judge(int x,int y) 9 { 10 int i,j; 11 for(i=0;i<4;i++) 12 { 13 if(a[x+dx[i]][y+dy[i]]=='.'&&b[x+dx[i]][y+dy[i]]==false&&x+dx[i]>=0&&y+dy[i]>=0&&x+dx[i]<m&&y+dy[i]<n) 14 { 15 b[x+dx[i]][y+dy[i]]=true; 16 ans++; 17 judge(x+dx[i],y+dy[i]); 18 } 19 } 20 } 21 int main() 22 { 23 int i,j; 24 while(scanf("%d %d",&n,&m),n,m) 25 { 26 memset(b,false,sizeof(b)); 27 for(i = 0;i < m;i++) 28 { 29 getchar(); 30 for(j = 0;j < n;j++) 31 { 32 scanf("%c",&a[i][j]); 33 if(a[i][j]=='@') 34 { 35 x=i; 36 y=j; 37 b[i][j]=true; 38 } 39 } 40 } 41 ans = 0; 42 judge(x,y); 43 printf("%d\n",ans+1); 44 } 45 return 0; 46 }