/in/foo.cc: In function 'void insert(int, int, int&)':
/in/foo.cc:68:11: warning: operation on 'tot' may be undefined [-Wsequence-point]
    key[rt=++tot]=hash0[tot]=ky;
           ^~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:145:13: warning: unused variable 'tmp' [-Wunused-variable]
   int m,x,y,tmp;
             ^~~
/in/foo.cc: In function 'int find_node(int)':
/in/foo.cc:99:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'long long unsigned int query(int, int)':
/in/foo.cc:125:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'void insert(int, int, int&)':
/in/foo.cc:83:13: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   son[pe][p]=tot;
   ~~~~~~~~~~^~~~
/in/foo.cc:83:13: warning: 'pe' may be used uninitialized in this function [-Wmaybe-uninitialized]