Compilare: user.cpp: In function ‘void cit(unsigned int&)’: user.cpp:19: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘long long int f(unsigned int)’: user.cpp:46: warning: comparison between signed and unsigned integer expressions user.cpp:37: warning: unused variable ‘j’ user.cpp: In function ‘int main()’: user.cpp:99: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result