Compilare: user.cpp: In member function ‘bool Graph::forms_cycle(Edge)’: user.cpp:77:6: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘void Graph::print_edges()’: user.cpp:97:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i++){ ^ user.cpp: In member function ‘void Graph::compute_mst()’: user.cpp:106:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1 ;i < v.size(); i++){ ^ user.cpp: In member function ‘void Graph::print_mst()’: user.cpp:120:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < mst_indexes.size(); i++){ ^ user.cpp: In function ‘int main()’: user.cpp:129:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in","r",stdin); ^ user.cpp:130:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdin); ^ user.cpp:132:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:136:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^