Compilare: user.cpp: In function ‘int main()’: user.cpp:49:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "decrease.in" , "r", stdin ); ^ user.cpp:50:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "decrease.out", "w", stdout ); ^ user.cpp:52:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d", &N ); ^ user.cpp:54:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d", &A[i] ); ^