Compilare: user.cpp: In function ‘int main()’: user.cpp:92:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int scc = 0; scc < sccs.size(); scc++) { ^ user.cpp:103:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int scc = 0; scc < sccs.size(); scc++) { ^ user.cpp:43:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(IA_PROB".in", "r", stdin); ^ user.cpp:44:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(IA_PROB".out", "w", stdout); ^ user.cpp:47:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:53:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^