Eroare de compilare: user.cpp:3:17: error: stdlib: No such file or directory user.cpp: In function ‘int main()’: user.cpp:76: error: ‘strlen’ was not declared in this scope user.cpp:77: error: ‘strcpy’ was not declared in this scope user.cpp:78: error: ‘atoi’ was not declared in this scope user.cpp:80: warning: comparison between signed and unsigned integer expressions