Compilare: main.cpp: In function 'bool is_in_stack(int, std::vector<int>&)': main.cpp:21:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for (int i = 0; i < stack.size(); ++i) { | ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:105:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 105 | for (int j = 0; j < scc[i].size(); ++j) | ~~^~~~~~~~~~~~~~~