Compilare: main.cpp: In member function 'void min_cost_flow::build()': main.cpp:24:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for(int j = 0;j < g[i].size();++j) | ~~^~~~~~~~~~~~~ main.cpp: In member function 'bool min_cost_flow::bellman(int&)': main.cpp:54:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 54 | for(int i = 0;i < graph[nod].size();++i) | ~~^~~~~~~~~~~~~~~~~~~