Compilare: user.cpp: In function ‘int main()’: user.cpp:80: warning: unused variable ‘c1’ user.cpp:80: warning: unused variable ‘c2’ user.cpp:80: warning: unused variable ‘c3’ user.cpp:80: warning: unused variable ‘l’ user.cpp:78: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:79: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result