foo.cc: In function 'int main()':
foo.cc:39:22: warning: 'id' may be used uninitialized [-Wmaybe-uninitialized]
   39 |                 c[i] = id;
      |                 ~~~~~^~~~
foo.cc:26:22: warning: 'id' may be used uninitialized in this function [-Wmaybe-uninitialized]
   26 |                 b[i] = id;
      |                 ~~~~~^~~~

[Hydro](https://hydro.ac)提供评测服务