Compilare: main.cpp: In function 'std::vector<std::pair<char, int> > solve2(std::vector<int>)': main.cpp:61:9: warning: unused variable 'x' [-Wunused-variable] 61 | int x; | ^ main.cpp: In function 'int main()': main.cpp:83:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<char, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 83 | for(int i=0;i<x.size();i++) | ~^~~~~~~~~