Compilare: user.cpp: In function ‘std::vector<Inversion> get_inversions(std::vector<unsigned int>&)’: user.cpp:15:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < data.size(); ++i) { ^ user.cpp:16:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i+1; j < data.size(); ++j) { ^ user.cpp:18:31: warning: narrowing conversion of ‘i’ from ‘int’ to ‘unsigned int’ inside { } [-Wnarrowing] inversions.push_back({i,j}); ^ user.cpp:18:31: warning: narrowing conversion of ‘j’ from ‘int’ to ‘unsigned int’ inside { } [-Wnarrowing] user.cpp: In function ‘int main()’: user.cpp:52:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < n; ++i) { ^ user.cpp:53:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < n; ++j) { ^