Compilare: user.cpp: In function ‘int hash(std::string)’: user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:83: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:84: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/ccaifRde.o: In function `main': user.cpp:(.text+0x6a3): warning: the `gets' function is dangerous and should not be used.