Compilare: user.cpp: In function ‘void dfs(int, char, char)’: user.cpp:36:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (scc[nscc].size() > lmax) { ~~~~~~~~~~~~~~~~~^~~~~~ user.cpp: In function ‘int main()’: user.cpp:47:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("plimbare.in", "r", stdin); ^ user.cpp:48:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("plimbare.out", "w", stdout); ^ user.cpp:50:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:53:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &u, &v); ^