Compilare: main.cpp: In member function 'void Residual_graph::add_edge(int, int, int)': main.cpp:30:34: warning: narrowing conversion of '(((Residual_graph*)this)->Residual_graph::G + ((sizetype)(((long unsigned int)v) * 24ul)))->std::vector<_Tp, _Alloc>::size<Edge, std::allocator<Edge> >()' from 'std::vector<Edge>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] Edge a{v, 0, cap, G[v].size()}; ~~~~~~~~~^~ main.cpp:31:32: warning: narrowing conversion of '(((Residual_graph*)this)->Residual_graph::G + ((sizetype)(((long unsigned int)u) * 24ul)))->std::vector<_Tp, _Alloc>::size<Edge, std::allocator<Edge> >()' from 'std::vector<Edge>::size_type {aka long unsigned int}' to 'int' inside { } [-Wnarrowing] Edge b{u, 0, 0, G[u].size()}; ~~~~~~~~~^~ main.cpp: In member function 'int Residual_graph::push_flow(int, int, int, int*)': main.cpp:68:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( ; start[node] < G[node].size(); start[node] ++ ) { ~~~~~~~~~~~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:100:17: warning: unused variable 'c' [-Wunused-variable] int a, b, c; ^