Compilare: user.cpp: In function ‘int main()’: user.cpp:17:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i+2<s.length();i++){ ^ user.cpp:19:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]<s[i-1] and s[i]<s[i+1] and i+2<s.length()) ^ user.cpp:36:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i+1<s.length();i++) ^