Compilare: main.cpp: In function 'void belman(int)': main.cpp:32:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | for(int j = 0; j<a[nod].size();++j) | ~^~~~~~~~~~~~~~