Compilare: user.cpp: In function ‘void topologica()’: user.cpp:49:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[nod].size(); ++j) ^ user.cpp: In function ‘void df(int)’: user.cpp:74:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[nod].size(); ++j) ^ user.cpp: In function ‘void solve()’: user.cpp:112:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:115:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:138:43: 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:139:45: 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:143:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^