Compilare: user.cpp: In function ‘int main(int, const char**)’: user.cpp:22:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (IN,"r",stdin); ^ user.cpp:23:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (OUT,"w",stdout); ^ user.cpp:27:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for ( scanf("%d",&T) ; T ; -- T) ^ user.cpp:29:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:31:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i=1; i <= N; ++i) scanf("%d",&V[i]); ^