Câu 44: CPP: C++ Certified Professional Programmer

What happens when you attempt to compile and run the following code?#include #include #include using namespace std;template struct Out {ostream & out;Out(ostream & o): out(o){}void operator() (const T & val ) { out d1(10);generate(d1.begin(), d1.end(), Sequence(1));sort(d1.begin(), d1.end());pair ::iterator, deque ::iterator > result = equal_range(d1.begin(), d1.end(), 20); for_each(result.first, result.second, Out (cout));cout<<endl; return 0;}Program outputs:

1. A. 10 10 10 20 20 20 20 30 30 30
2. B. 20 20 20 20 — đáp án hiện tại
3. C. 10 20 20 20 20
4. D. 20 20 20 20 30
5. E. 10 20 20 20 20 30