老师教的

#include<iostream>
using namespace std;
int main(){
int n,m,b[1010][1010];
char a[1010][1010];
cin>>n>>m;
for(int i=1;i<=n;i+=1){
for(int j=1;j<=m;j+=1){
cin>>a[i][j];
}
}
for(int i=1;i<=n;i+=1){
for(int j=1;j<=m;j+=1){
if(a[i][j]'*'){
b[i-1][j-1]+=1;
b[i-1][j]+=1;
b[i-1][j+1]+=1;
b[i][j-1]+=1;
b[i][j+1]+=1;
b[i+1][j-1]+=1;
b[i+1][j]+=1;
b[i+1][j+1]+=1;
}
}
}
for(int i=1;i<=n;i+=1){
for(int j=1;j<=m;j+=1){
if(a[i][j]''){
cout<<"";
}
else{
cout<<b[i][j];
}
}
cout<<endl;
}
}