Compilare: user.cpp: In member function ‘void network::add_edge(int, int, int)’: user.cpp:13:42: warning: narrowing conversion of ‘(((network*)this)->network::muc.std::vector<_Tp, _Alloc>::size<network::edge, std::allocator<network::edge> >() + 1u)’ from ‘std::vector<network::edge>::size_type {aka unsigned int}’ to ‘int’ inside { } [-Wnarrowing] muc.push_back({y,c,muc.size()+1}); ^ user.cpp:14:42: warning: narrowing conversion of ‘(((network*)this)->network::muc.std::vector<_Tp, _Alloc>::size<network::edge, std::allocator<network::edge> >() + 4294967295u)’ from ‘std::vector<network::edge>::size_type {aka unsigned int}’ to ‘int’ inside { } [-Wnarrowing] muc.push_back({x,0,muc.size()-1}); ^ user.cpp: In function ‘int main()’: user.cpp:77:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("smart.in", "r", stdin); ^ user.cpp:78:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("smart.out", "w", stdout); ^ user.cpp:80:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:81:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;i++) scanf("\n%s",sir[i]+1); ^ user.cpp:79:20: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,k,nr=0,a,b,flow=0,t; ^ user.cpp:13:45: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] muc.push_back({y,c,muc.size()+1}); ^ user.cpp:79:18: note: ‘a’ was declared here int n,k,nr=0,a,b,flow=0,t; ^