Compilare: user.cpp: In function ‘int main()’: user.cpp:62:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G.size();i++){ ^ user.cpp:71:42: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 3 has type ‘std::vector<long int>::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n%ld\n",ans,aEdges.size()); ^ user.cpp:72:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<aEdges.size();i++) printf("%ld %ld\n",G[cEdge].n1,G[cEdge].n2); ^ user.cpp:51:32: 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:52:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out","w",stdout); ^ user.cpp:54:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:56:55: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld",&tmp.n1,&tmp.n2,&tmp.cost); ^