Compilare: user.cpp: In function ‘int main()’: user.cpp:94:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int scc = 0; scc < sccs.size(); scc++) { ^ user.cpp:105:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int scc = 0; scc < sccs.size(); scc++) { ^ user.cpp:35:35: 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:36:37: 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:39:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:57:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); // a or b ^