foo.cc: In function ‘bool cmp(st, st)’:
foo.cc:10:37: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   10 |                         x.all==y.all&&x.ch>y.ch
      |                         ~~~~~~~~~~~~^~~~~~~~~~~
foo.cc:12:35: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   11 |                         ||x.all==y.all&&
      |                           ~~~~~~~~~~~~~~
   12 |                         x.ch==y.ch&&x.id<y.id;
      |                         ~~~~~~~~~~^~~~~~~~~~~