foo.cc: In function 'int main()':
foo.cc:12:26: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   12 |                 if(y%4==0&&y%100!=0||y%400==0)
      |                    ~~~~~~^~~~~~~~~~
foo.cc:17:15: warning: 'c' may be used uninitialized [-Wmaybe-uninitialized]
   17 |         cout<<c;
      |               ^
foo.cc:5:17: note: 'c' was declared here
    5 |         int y,m,c;
      |                 ^

[Hydro](https://hydro.ac)提供评测服务