#include<bits/stdc++.h>
using namespace std;
int b[101][101],n,m,xx,yy,head,tail,num=-1;
int dx[5]={0,-1,1,0,0};
int dy[5]={0,0,0,-1,1};
struct JF{
	int x,y;
}YY[10001];
int main() {
	cin>>n>>m;
	char ch;
	for (int i=1;i<=n;i++) {
		for (int j=1;j<=m;j++) {
			cin>>ch;
			if (ch=='0') b[i][j]=0;
			else b[i][j]=ch-'0';
		}
	}
	for (int i=1;i<=n;i++) {
		for (int j=1;i<=m;j++) {
			if (b[i][j]==0) continue;
			num++;
			head=0,tail=1;
			YY[1].x=i;
			YY[1].y=j;
			b[i][j]=0;
			while (head<tail) {
				head++;
				for (int k=1;k<=4;k++) {
					int xx=YY[head].x+dx[k];
					int yy=YY[head].y+dy[k];
					if (b[xx][yy]!=0) {
						tail++;
						b[xx][yy]=0;
						YY[tail].x=xx;
						YY[tail].y=yy;
					}
				}
			}  
		}
	}
	cout<<num;
	return 0;
}

样例能过但全RE

记录: https://www.luogu.com.cn/record/199068743