打了半天没对，谁能帮我找找有啥问题。

# include <bits/stdc++.h>
using namespace std;
char a[105][105],ch;
int n,m,xx[]={-1,-1,-1,0,0,1,1,1},yy[]={-1,0,1,-1,1,-1,0,1};
int main()
{
	cin>>n>>m;
    memset(a,'0',sizeof(a));
    /*for (int u=1;u<=103;u++)
        for (int v=1;v<=103;v++)
            a[u][v]='0';*/
	for (int u=1;u<=n;u++)
        for (int v=1;v<=m;v++)
        {
            cin>>ch;
            if (ch=='*')
		    {
		    	a[u][v]='*';
		    	for (int w=0;u<8;u++)
		    	{   
                    int ux=xx[w]+u,uy=yy[w]+v;
                    if (ux>0&&ux<=n&&uy>0&&uy<=m&&a[ux][uy]!='*')
		    			a[ux][uy]=char(a[ux][uy]+1); 
                }
		    }
        }	
	for (int u=1;u<=n;u++)
    {
        for (int v=1;v<=m;v++)
			cout<<a[u][v];
        cout<<'\n';
    }
	
	return 0;
}