Compilare: main.cpp: In function 'int main()': main.cpp:61:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 61 | for (i=0;i<a.size();i++) | ~^~~~~~~~~ main.cpp:62:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for (int j=i+1;j<a.size();j++) | ~^~~~~~~~~ main.cpp:60:20: warning: unused variable 'vf' [-Wunused-variable] 60 | long long vf=0; | ^~