/in/foo.cc: In function 'u Swap0(int, int)':
/in/foo.cc:32:17: warning: 't2' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (u){s+t2*shi[p]+t1*shi[1],p};
               ~~^~~~~~~
/in/foo.cc:32:27: warning: 't1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (u){s+t2*shi[p]+t1*shi[1],p};
                         ~~^~~~~~~
/in/foo.cc: In function 'u Swap1(int, int)':
/in/foo.cc:50:17: warning: 't2' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (u){s+t2*shi[p]+t1*shi[6],p};
               ~~^~~~~~~
/in/foo.cc:50:27: warning: 't1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return (u){s+t2*shi[p]+t1*shi[6],p};
                         ~~^~~~~~~
/in/foo.cc: In function 'u Up(int, int)':
/in/foo.cc:65:5: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
  q++;
     ^
/in/foo.cc: In function 'u Down(int, int)':
/in/foo.cc:82:5: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
  q--;
     ^
/in/foo.cc: In function 'void bfs()':
/in/foo.cc:82:5: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
  q--;
     ^
/in/foo.cc:71:20: note: 'q' was declared here
  int pp=6,aa=a,s=0,q;
                    ^
/in/foo.cc:65:5: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
  q++;
     ^
/in/foo.cc:54:20: note: 'q' was declared here
  int pp=6,aa=a,s=0,q;
                    ^