/in/foo.cc: In function 'int main()':
/in/foo.cc:24:15: warning: unused variable 'k' [-Wunused-variable]
   int s=S,t=T,k;
               ^
/in/foo.cc: In function 'int one(int)':
/in/foo.cc:15:9: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return i;
         ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:36:5: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if(one(t+1)<one(t-1))
     ^~
/in/foo.cc:36:5: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
/in/foo.cc:34:5: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]
     if(one(t+1)>one(t-1))
     ^~
/in/foo.cc:34:5: warning: 'i' may be used uninitialized in this function [-Wmaybe-uninitialized]