Compilare: user.cpp: In function ‘int hash(char*)’: user.cpp:13: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:51: warning: unused variable ‘sum’ user.cpp:55: warning: unused variable ‘b’ user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result