poj1979 bfs

#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
//简单bfs开始把行列搞错了
struct Node
{
    int x;
    int y;//坐标
    int cnt;//步数
    Node(int a,int b,int c):x(a),y(b),cnt(c) {}
};
char rec[30][30];
int w,h,x1,y1;
int nowx,nowy,nowc;
bool vis[30][30];
int direction[4][2]= {{-1,0},{1,0},{0,-1},{0,1}}; //上下左右
queue<Node> q;
int bfs(int x,int y)
{

    int ans = 1;
    q.push(Node(x,y,1));
    vis[x][y] = 1;
    while(!q.empty())
    {
        Node  now = q.front();
        q.pop();
        for(int i = 0; i<4; ++i)
        {
            x1 = now.x + direction[i][0];
            y1 = now.y + direction[i][1];
            if(x1<h&&x1>=0&&y1<w&&y1>=0&&rec[x1][y1]!='#'&&!vis[x1][y1])
            {
                q.push(Node(x1,y1,now.cnt+1));
                ans++;
                vis[x1][y1] = 1;
            }
        }
    }
    return ans;
}
int main()
{
    char c;
    int x,y;
    while(scanf("%d%d",&w,&h),w)
    {
        memset(vis,0,sizeof(vis));
        for(int i = 0; i<h; ++i)
        {
            getchar();
            for(int j = 0; j<w; ++j)
            {
                scanf("%c",&rec[i][j]);
                if(rec[i][j]=='@')
                {
                    x = i;
                    y = j;
                }
            }
        }
        printf("%d\n",bfs(x,y));
    }
    return 0;
}