/in/foo.cc: In function 'int main()':
/in/foo.cc:49:17: warning: 'qq' may be used uninitialized in this function [-Wmaybe-uninitialized]
    if(tx==pp&&ty==qq)
               ~~^~~~
/in/foo.cc:49:9: warning: 'pp' may be used uninitialized in this function [-Wmaybe-uninitialized]
    if(tx==pp&&ty==qq)
       ~~^~~~
/in/foo.cc:37:12: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
  book[p][q]=1;
  ~~~~~~~~~~^~
/in/foo.cc:37:12: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]