/in/foo.cc: In function 'int SG(int)':
/in/foo.cc:20:9: warning: unused variable 'i' [-Wunused-variable]
     int i, t;    
         ^
/in/foo.cc:20:12: warning: unused variable 't' [-Wunused-variable]
     int i, t;    
            ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:72:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<strlen(str); i++)if(str[i]!='.')str[i]='X';
                  ~^~~~~~~~~~~~
/in/foo.cc: In function 'int SG(int)':
/in/foo.cc:32:1: warning: control reaches end of non-void function [-Wreturn-type]
 }    
 ^