不知道难不难的代码

#include<bits/stdc++.h>
using namespace std;

char sure(int e)
{
	if(e == 0) return '0';
	if(e == 1) return '1';
	if(e == 2) return '2';
	if(e == 3) return '3';
	if(e == 4) return '4';
	if(e == 5) return '5';
	if(e == 6) return '6';
	if(e == 7) return '7';
	if(e == 8) return '8';
	if(e == 9) return '9';
	
}

int main(){
	int qwe;
    char a[105][105];
    int n,m;

    cin >> n >> m;

    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            cin >> a[i][j];
        }
    }
    
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            if(a[i][j] == '*')
				a[i][j] = '*';
            else 
            {
            	int e = 0;
            	if(a[i-1][j-1] == '*') e++;
            	if(a[i][j-1] == '*') e++;
            	if(a[i+1][j-1] == '*') e++;
            	
            	if(a[i-1][j] == '*') e++;
            	if(a[i+1][j] == '*') e++;
            	
            	if(a[i+1][j+1] == '*') e++;
            	if(a[i][j+1] == '*') e++;
            	if(a[i-1][j+1] == '*') e++;
            	
				a[i][j] = sure(e);
			}
        }
    }

    
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
        	cout << a[i][j];
        }
        cout << endl;
    }
    
    return 0;
}