/in/foo.c:3:5: error: variably modified 'a' at file scope
 int a[N];
     ^
/in/foo.c: In function 'main':
/in/foo.c:7:12: warning: format '%d' expects a matching 'int *' argument [-Wformat=]
  scanf("%d%d",&n);
            ^
/in/foo.c:21:18: error: lvalue required as left operand of assignment
   if(a[i]==0&&zxc=1)
                  ^