Compilare: main.cpp: In function 'int main()': main.cpp:71:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | for (int i = 0; i < odd.size(); i += 2) | ~~^~~~~~~~~~~~ main.cpp:79:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 79 | for (int i = 1; i < ans_euler.size() - 1; i++) | ~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp:91:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 91 | for (int j = 0; j < ans[i].size(); j++) | ~~^~~~~~~~~~~~~~~