Compilare: user.cpp: In function ‘int main()’: user.cpp:86:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < Exp.size(); ++i) ^ user.cpp:55:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.in","r",stdin); ^ user.cpp:56:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.out","w",stdout); ^ user.cpp:60:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d", &T); T ; --T) ^ user.cpp:62:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:71:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &node1, &node2); ^