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 main()’:
answer.code:35:16: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   35 |         freopen("in.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cclLjAaW.o: in function `main':
answer.code:(.text.startup+0x0): multiple definition of `main'; /tmp/ccs8vD8W.o:implementer.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccs8vD8W.o: in function `main':
implementer.cpp:(.text.startup+0x12b): undefined reference to `init(int)'
/usr/bin/ld: implementer.cpp:(.text.startup+0x1d0): undefined reference to `inv(int)'
collect2: error: ld returned 1 exit status