Compilare: main.cpp: In function 'std::pair<int, int> sub(std::vector<int>)': main.cpp:61:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 61 | for (int i = 0; i < a.size(); i++) | ~~^~~~~~~~~~ main.cpp:62:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for (int j = i + 1; j < a.size(); j++) | ~~^~~~~~~~~~