Compilare: user.cpp:51:17: warning: multi-character character constant [-Wmultichar] out << k << '/n'; ^ user.cpp: In function ‘int main()’: user.cpp:29:68: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(*cool.rbegin() - *cool.begin() == k-1 && k == cool.size()) ^ user.cpp:37:72: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(*cool.rbegin() - *cool.begin() == k-1 && k == cool.size()) ^