Compilare: user.cpp: In function ‘int main()’: user.cpp:56:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapeze2.in","r",stdin); ^ user.cpp:57:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapeze2.out","w",stdout); ^ user.cpp:59:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld",&x1,&d1,&n1); x1 <<= 1; d1 <<= 1; ^ user.cpp:60:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld",&x2,&d2,&n2); x2 <<= 1; d2 <<= 1; ^