Problem 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.
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)
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
.#########.
...........
11 6
..#..#..#..
..#..#..#..
..#..#..###
..#..#..#@.
..#..#..#..
..#..#..#..
7 7
..#.#..
..#.#..
###.###
...@...
###.###
..#.#..
..#.#..
0 0
Sample Output
45
59
6
13
#include<iostream>
using namespace std;
char mapp[][];
int m,n,k=,c=,d=;
void dfs(int x,int y)
{
if(mapp[x][y]=='#'||x<||y<||x>=m||y>=n)
{
return;
}
mapp[x][y]='#';
dfs(x+,y);
dfs(x-,y);
dfs(x,y+);
dfs(x,y-);
}
int main()
{
int i,j,k;
while(cin>>n>>m)
{
c=;
d=;
if(m==&&n==)
break;
for(i=;i<m;i++)
{
for(j=;j<n;j++)
{
cin>>mapp[i][j];
}
}
for(i=;i<m;i++)
for(j=;j<n;j++)
{
if(mapp[i][j]=='#')
c++;
}
k=;
for(i=;i<m;i++)
{
for(j=;j<n;j++)
{
if(mapp[i][j]=='@')
{
mapp[i][j]='.';
dfs(i,j);
}
}
}
for(i=;i<m;i++)
for(j=;j<n;j++)
{
if(mapp[i][j]=='#')
d++;
}
cout<<d-c<<endl;
}
return ;
}