Compilare: user.cpp: In function ‘void task1(const std::vector<std::basic_string<char> >&, std::ostream&)’: user.cpp:17:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < words.size() - 1; i++){ ^ user.cpp: In function ‘int main()’: user.cpp:46:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < priority.size(); i++){ ^ user.cpp: In lambda function: user.cpp:58:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return i < s1.size() && mapping[s1[i]] < mapping[s2[i]]; ^