HDU 1312 Red and Black

 

http://acm.hdu.edu.cn/showproblem.php?pid=1312

从这老题开始吧

View Code

#include <iostream>

#include <queue>

using namespace std ;

char map[25][25];

int ans,n,m;

typedef struct L{

    int x,y;

}L;

void bfs(int x,int y)

{

    queue <L> q ;

    int tab[][2]={1,0,-1,0,0,1,0,-1};

    L point,go,front;

    point.x=x;

    point.y=y;

    q.push(point);

    map[x][y]='#';

    while(!q.empty())

    {

        front=q.front();

        q.pop();

        for(int i=0;i<4;i++)

        {

            go.x=front.x+tab[i][0];

            go.y=front.y+tab[i][1];

            if(go.x>=0&&go.x<n&&go.y>=0&&go.y<m&&map[go.x][go.y]=='.')

            {

                ans++;

                q.push(go);

                map[go.x][go.y]='#';

            }

        }

    }

}

int main()

{

    while(scanf("%d%d",&m,&n),(m||n))

    {

        for(int i=0;i<n;i++)

            scanf("%s",map[i]);

        int x,y;

        for(int i=0;i<n;i++)

            for(int j=0;j<m;j++)

                if(map[i][j]=='@')

                    x=i,y=j;

        ans=1;

        bfs(x,y);

        printf("%d\n",ans);

    }

    return 0;

}