Eroare de compilare: user.cpp: In function ‘int hash(std::string)’: user.cpp:17: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:86: error: ‘strlen’ was not declared in this scope user.cpp:82: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:83: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:85: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:85: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result