/in/foo.cc: In function 'void build(int&, int, int)':
/in/foo.cc:30:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid = l + r >> 1; o = id[mid];
            ~~^~~
/in/foo.cc: In function 'void splay(int)':
/in/foo.cc:49:16: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
    if(ch[0][y] == u ^ ch[0][z] == y) rotate(u);
       ~~~~~~~~~^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:111:4: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
    if(rk < 1 || rk > n) continue; rk = Find(getrt(), rk);
    ^~
/in/foo.cc:111:35: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
    if(rk < 1 || rk > n) continue; rk = Find(getrt(), rk);
                                   ^~
/in/foo.cc:96:6: warning: unused variable 'tq' [-Wunused-variable]
  int tq = q;
      ^~