#include<bits/stdc++.h>
using namespace std;
int n,m,ans;
int dx[4]={-1,0,0,1};
int dy[4]={0,-1,1,0};
char a;
int aa[110][110];
void dfs(int x,int y)
{
    for(int i=0;i<4;i++)
    { 
        int xx=x+dx[i];
        int yy=y+dy[i];
        if(aa[xx][yy]!=0&&xx>=1&&yy>=1&&xx<=n&&yy<=m)
        {
            
            dfs(xx,yy);
        }
    }
}
int main()
{
    cin>>n>>m;
    for (int i = 1; i <= n; i ++ )
    {
        for (int j = 1; j <= m; j ++ )
        {
            cin>>a;
            aa[i][j]=a-'0';
        }

    }
    for (int i = 1; i <= n; i ++ )
    {
        for (int j = 1; j <= m; j ++ )
        {
            if(aa[i][j]!=0)
            {
                dfs(i,j);
                aa[i][j]=1;
                
            }
        
        }
       
    }
    for (int i = 1; i <= n; i ++ )
    {
        for (int j = 1; j <= m; j ++ )
        {
            if(aa[i][j]!=0)
            {
                ans++;
            }
        
        }
       
    }
    
    cout<<ans<<endl;
}

用了dfs感觉也没有可以剪枝的部分了呀，请指教一下