foo.cc: In function ‘int main()’:
foo.cc:7:18: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
    7 |         if(y%4==0&&y%100!=0||y%400==0)
      |            ~~~~~~^~~~~~~~~~
foo.cc:8:10: error: ‘leap’ was not declared in this scope
    8 |          leap=0;
      |          ^~~~
foo.cc:11:33: error: ‘leap’ was not declared in this scope
   11 |                 case 2:cout<<28+leap;break;
      |                                 ^~~~