/in/foo.cc: In function 'bool func(int)':
/in/foo.cc:5:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
     if(y%4==0&&y%100!=0||y%400==0){
        ~~~~~~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:12:17: warning: unused variable 'days' [-Wunused-variable]
     int i,y,m,d,days=-1;
                 ^~~~