foo.cc: In function 'int main()':
foo.cc:12:13: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   12 |     a[x][y]="*";
      |             ^~~
      |             |
      |             const char*
foo.cc:17:17: warning: comparison with string literal results in unspecified behavior [-Waddress]
   17 |     if(a[i][j]!="*")
      |                 ^~~
foo.cc:17:17: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
foo.cc:21:40: warning: comparison with string literal results in unspecified behavior [-Waddress]
   21 |        s+=a[i+dir[k][0]][j+dir[k][1]]=="*";
      |                                        ^~~
foo.cc:21:40: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
foo.cc:22:13: error: invalid conversion from 'const char*' to 'char' [-fpermissive]
   22 |    a[i][j]=s+"0";
      |            ~^~~~
      |             |
      |             const char*

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