Compilare: user.cpp:47:17: warning: multi-character character constant [-Wmultichar] cout << '-1'; ^ user.cpp: In function ‘void euler(int)’: user.cpp:20:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[nod].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:42:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sol.size() == m) { ^ user.cpp:43:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); i++) { ^