coins.cpp:35:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
35 | main(){
| ^~~~
/usr/bin/ld: /tmp/ccp6fubg.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc8EQOav.o:coins.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/ccp6fubg.o: in function `main':
grader.cpp:(.text.startup+0x3e2): undefined reference to `coin_flips(std::vector<int, std::allocator<int> >, int)'
/usr/bin/ld: grader.cpp:(.text.startup+0xb8a): undefined reference to `find_coin(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status