/in/foo.cc: In function 'bool cmp(int, int, int, int)':
/in/foo.cc:52:70: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  return cnt[lb][rb][x]>cnt[lb][rb][y]||cnt[lb][rb][x]==cnt[lb][rb][y]&&x<y;
                                                                      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:109:5: warning: operation on 't' may be undefined [-Wsequence-point]
   l[++t]=r[t-1]+1,r[t]=n;
     ^~~