(简单) POJ 1562 Oil Deposits，BFS。

#include<iostream>
#include<cstring>

using namespace std;

int vis[110][110];
int ans;
int M,N;
int fir,las,que[10005];

bool judge(int x,int y)
{
    if(x<=0||y<=0||x>M||y>N)
        return 0;

    if(vis[x][y]==0)
        return 0;

    return 1;
}

void bfs(int x,int y)
{
    int temp,t1,t2;

    que[las++]=x*1000+y;
    vis[x][y]=0;

    while(las-fir)
    {
        temp=que[fir++];

        t1=temp/1000;
        t2=temp%1000;

        --t1;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }
        t1+=2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }    
        --t1;
        --t2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }    
        t2+=2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }
        t2-=2;
        --t1;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }    
        t1+=2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }    
        t2+=2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }    
        t1-=2;
        if(judge(t1,t2))
        {
            vis[t1][t2]=0;
            que[las++]=t1*1000+t2;
        }
    }
}

void slove()
{
    ans=0;
    fir=las=0;
    
    for(int i=1;i<=M;++i)
        for(int j=1;j<=N;++j)
            if(vis[i][j])
            {
                ++ans;
                bfs(i,j);
            }
}

int main()
{
    ios::sync_with_stdio(false);
    
    char c;

    for(cin>>M>>N;M;cin>>M>>N)
    {
        for(int i=1;i<=M;++i)
            for(int j=1;j<=N;++j)
            {
                cin>>c;
                vis[i][j]=c==‘@‘?1:0;
            }

        slove();
        cout<<ans<<endl;
    }

    return 0;
}