Eroare de compilare: user.cpp:10: warning: deprecated conversion from string constant to ‘char*’ user.cpp: In function ‘void back(int, int)’: user.cpp:20: warning: comparison between signed and unsigned integer expressions user.cpp:27: warning: comparison between signed and unsigned integer expressions user.cpp:34: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:62: error: ‘strlen’ was not declared in this scope user.cpp:64: error: ‘strchr’ was not declared in this scope