foo.cc: In function 'int Year(int)':
foo.cc:29:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  return y%4==0&&y%100!=0||y%400==0;
         ~~~~~~^~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:16:3: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
  t+=d1;
  ~^~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。