hdu 1312 Red and Black

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

 

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 ;
}