Compilare: main.cpp: In function 'int main()': main.cpp:12:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp:17:92: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (cuvant == true && (s[i] < 'A' || (s[i] > 'Z' && s[i] < 'a') || s[i] > 'z' || i == s.size() - 1)) { ~~^~~~~~~~~~~~~~~