Compilare: main.cpp: In function 'void make_chain(int)': main.cpp:115:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[node].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:151:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pandemie.in", "r", stdin); ^ main.cpp:152:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pandemie.out", "w", stdout); ^