Compilare: user.cpp: In function ‘int main()’: user.cpp:13:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size()-1&&s[i]>=s[i+1]) ^ user.cpp:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size()-1) ^ user.cpp:17:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s.size()-1&&s[i]>=s[i+1]) ^ user.cpp:20:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s[i]>=s[i+1]&&i<s.size()-1) ^ user.cpp:24:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[i]<=s[i+1]&&i<s.size()-1) ^ user.cpp:27:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<s.size()-1&&s[i]<=s[i+1]) ^