Compilare: user.cpp: In function ‘std::vector<std::vector<std::vector<int> > > generateVariations(int)’: user.cpp:11:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < variations.size(); i++) ^ user.cpp:14:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < variations[i].size(); j++) ^ user.cpp:24:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < variations[i][j].size(); k++) ^ user.cpp: In function ‘std::vector<int> count(int)’: user.cpp:39:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < variations.size(); i++) ^ user.cpp:41:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < variations[i].size(); j++) ^ user.cpp:43:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k = 0; k < variations[i][j].size(); k++) ^ user.cpp: In function ‘void print(std::ostream&, std::vector<int>)’: user.cpp:78:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size() - 1; i++) ^ user.cpp:84:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:127:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < cnt.size(); i++) ^