Compilare: user.cpp: In function ‘int main()’: user.cpp:22:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^ user.cpp:33:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size()-2;i++) ^ user.cpp:54:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<cpy.size()) ^ user.cpp:70:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size()-2;i++) ^ user.cpp:84:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i+1;j<s.size();j++) ^