/usr/bin/ld: /tmp/ccnGoYKt.o: in function `main': grader.cpp:(.text.startup+0x25e): undefined reference to `max_weights(int, int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >)' collect2: error: ld returned 1 exit status