foo.c: In function 'main':
foo.c:8:9: error: variable-sized object may not be initialized
    8 |         int a[L+1]={0};
      |         ^~~
foo.c:19:13: error: 'i' undeclared (first use in this function)
   19 |         for(i=0;i<=L;i++)
      |             ^
foo.c:19:13: note: each undeclared identifier is reported only once for each function it appears in
foo.c:8:13: warning: variable 'a' set but not used [-Wunused-but-set-variable]
    8 |         int a[L+1]={0};
      |             ^

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