有点硬解成分

#include<iostream>
using namespace std;
int main(){
int n, m, x[1005][1005];
cin>>n>>m;
char a[1005][1005];
for(int i=0;i<n;i++){
for(int f=0;f<m;f++){
cin>>a[i][f];
if(a[i][f] == ''){
x[i][f+1] += 1;
x[i][f-1] += 1;
x[i-1][f+1] += 1;
x[i-1][f] += 1;
x[i-1][f-1] += 1;
x[i+1][f+1] += 1;
x[i+1][f] += 1;
x[i+1][f-1] += 1;
}
}
}
for(int i=0;i<n;i++){
for(int f=0;f<m;f++){
if(a[i][f] == ''){
cout<<a[i][f];
}
else{
cout<<x[i][f];
}
}
cout<<endl;
}
return 0;
}