Compilare: main.cpp: In function 'std::vector<int> solution(std::vector<int>)': main.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for( int i = 0; i < v.size(); ++i ) | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:45:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | for( i = 0; i < a.size(); ++i ) { | ~~^~~~~~~~~~