Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:25: error: ‘system’ was not declared in this scope user.cpp:26: error: redeclaration of ‘int state’ user.cpp:24: error: ‘int state’ previously declared here user.cpp:24: warning: unused variable ‘state’ user.cpp:9: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:10: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result