Compilare: user.cpp: In function ‘int prim(int)’: user.cpp:43:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vinv[nod].size(); ++i) ^ user.cpp:47:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v[fiu].size()==niv+1) ^ user.cpp: In function ‘int main()’: user.cpp:66:43: 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:67:44: 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:72:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ user.cpp:78:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:88:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^