Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:44:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q[nrop].dep.size(); ++ i) ^ user.cpp:47:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q[nrop].vec.size(); ++ i) ^ user.cpp: In function ‘int main()’: user.cpp:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.in", "r", stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("undo.out", "w", stdout); ^ user.cpp:59:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i", &n, &m); ^ user.cpp:62:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &type); ^ user.cpp:65:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i %i", &x, &y, &z); ^ user.cpp:72:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i", &x, &y); ^ user.cpp:76:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &x); ^