Compilare: user.cpp: In function ‘int main()’: user.cpp:30:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nustiu.in","r",stdin);cin.sync_with_stdio(false);cin.tie(0); ^ user.cpp:31:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nustiu.out","w",stdout);cout.sync_with_stdio(false);cout.tie(0); ^