Compilare: user.cpp: In function ‘int main()’: user.cpp:22:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pizza.in","r",stdin); ^ user.cpp:23:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pizza.out","w",stdout); ^ user.cpp:26:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] rep(i,1,n+1) scanf("%d", a + i); ^