Compilare: main.cpp: In function 'void euler(int)': main.cpp:23:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[node].size(); ++i) ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:40:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in", "r", stdin); ^ main.cpp:41:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out", "w", stdout); ^