Compilare: user.cpp: In function ‘int main()’: user.cpp:159: warning: comparison between signed and unsigned integer expressions user.cpp:168: warning: comparison between signed and unsigned integer expressions user.cpp:111: warning: unused variable ‘start’ user.cpp:194: warning: unused variable ‘stop’ user.cpp:113: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:114: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:116: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:124: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:132: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result