Compilare: main.cpp: In member function 'void maxFlow::addEdge(int, int, int)': main.cpp:27:46: warning: narrowing conversion of '(&((maxFlow*)this)->maxFlow::g.std::vector<_Tp, _Alloc>::operator[]<std::vector<Edge>, std::allocator<std::vector<Edge> > >(((std::vector<std::vector<Edge> >::size_type)to)))->std::vector<_Tp, _Alloc>::size<Edge, std::allocator<Edge> >()' from 'std::vector<Edge>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[from].push_back({to, 0, cap, g[to].size()}); ~~~~~~~~~~^~ main.cpp:28:49: warning: narrowing conversion of '((&((maxFlow*)this)->maxFlow::g.std::vector<_Tp, _Alloc>::operator[]<std::vector<Edge>, std::allocator<std::vector<Edge> > >(((std::vector<std::vector<Edge> >::size_type)from)))->std::vector<_Tp, _Alloc>::size<Edge, std::allocator<Edge> >() - 1ul)' from 'std::vector<Edge>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] g[to].push_back({from, 0, 0, g[from].size() - 1}); ~~~~~~~~~~~~~~~^~~ main.cpp: In member function 'bool maxFlow::bfs()': main.cpp:39:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int h = 0; h < g[node].size(); h++){ ~~^~~~~~~~~~~~~~~~ main.cpp: In member function 'int maxFlow::dfs(int, int)': main.cpp:53:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int &h = rem[node]; h < g[node].size(); h++){ ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:83:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in", "r", stdin); ^ main.cpp:84:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out", "w", stdout); ^ main.cpp:87:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:91:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &u, &v, &c); ^