foo.cc: In function 'int jd(Node*, int*)':
foo.cc:34:14: warning: statement has no effect [-Wunused-value]
   34 |         for (p; p != NULL; q = p, p = p->next)
      |              ^
foo.cc:44:16: warning: 'x' may be used uninitialized [-Wmaybe-uninitialized]
   44 |         return x;
      |                ^
foo.cc:31:13: note: 'x' was declared here
   31 |         int x;
      |             ^

[Hydro](https://hydro.ac)提供评测服务