计算机病毒

#include <iostream>
using namespace std;
int main() {
    int n,m,sum = 0;
    cin>>n;
    char a[n+1][n+1];
    for(int i = 1;i<=n;i++){
        for(int j = 1;j<=n;j++){
            cin>>a[i][j];
        }
    }
    cin>>m;
    for(int p = 1;p<m;p++){
        for(int i = 1;i<=n;i++){
            for(int j = 1;j<=n;j++){
                if(a[i][j]=='@'){
                    for(int y = 0;y<=2;y+=2){
                        if(a[i-1+y][j]=='*'){
                            sum++;
                            a[i-1+y][j] = '@';
                        }
                        if(a[i][j-1+y]=='*'){
                            sum++;
                            a[i][j-1+y] = '@';
                        }
                    }
                }
            }
        }
    }
    cout<<sum;
    return 0;
}