codevs 1569 最佳绿草

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<string>
#include<queue>

using namespace std;
const int N=101;
const int xd[]={0,-1,0,1};
const int yd[]={-1,0,1,0};

struct node{
    int x,y;
}now,top,nxt;
char a[N][N]; 
bool vis[N][N];
int answer;
int n,m;
queue<node>q;

inline int read()
{
    int x=0;char c=getchar();
    while(c<‘0‘||c>‘9‘)c=getchar();
    return x=c-‘0‘;
}

inline void bfs(int x,int y)
{
    
    answer++;
    now.x=x;
    now.y=y;
    q.push(now);
    vis[x][y]=1;
    
    while(!q.empty())
    {
        top=q.front();
        q.pop();
        for(int i=0;i<4;i++)
        {
            int xx=xd[i]+top.x;
            int yy=yd[i]+top.y;
            if(a[xx][yy]&&xx>0&&xx<=n&&yy>0&&yy<=m)
            {
                a[xx][yy]=0;
                nxt.x=xx;
                nxt.y=yy;
                q.push(nxt);
            }
        }
    }
}

int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
        {
            char c;
            cin>>c;
            if(c==‘#‘)a[i][j]=1;
            else a[i][j]=0;
        }
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            if(a[i][j])
                bfs(i,j);
                    
    printf("%d",answer);
    return 0;
}