Compilare: main.cpp: In function 'void df(int)': main.cpp:22:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for (int i = 0; i < l[vf].size() && grad[vf]; i++) | ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:56:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 56 | for (i = 0; i < sol.size(); i++) | ~~^~~~~~~~~~~~ main.cpp:59:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | for (j = 0; j < sol[i].size(); j++) | ~~^~~~~~~~~~~~~~~