implementer.cpp: In function ‘int main()’:
implementer.cpp:22:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   22 |         scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
answer.code: In function ‘int inv(int)’:
answer.code:11:13: warning: pointer to a function used in arithmetic [-Wpointer-arith]
   11 | return inv[x];
      |             ^
answer.code:11:13: error: invalid conversion from ‘int (*)(int)’ to ‘int’ [-fpermissive]
   11 | return inv[x];
      |             ^
      |             |
      |             int (*)(int)