/in/foo.cc: In function 'void splay(int, int&)':
/in/foo.cc:82:25: warning: suggest parentheses around comparison in operand of '^' [-Wparentheses]
             if (c[z][0] == y ^ c[y][0] == x) rotate(x, k);
                 ~~~~~~~~^~~~
/in/foo.cc:81:12: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
         if (y != k) 
            ^