foo.cc: In function 'int main()':
foo.cc:47:17: warning: 'L' may be used uninitialized in this function [-Wmaybe-uninitialized]
   47 |    sum += (k*p->coef);
      |              ~~~^~~~
foo.cc:57:15: note: 'L' was declared here
   57 |  PolyLinkList L(n);
      |               ^

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