Speed comparison of unordered_multiset

test.cpp

#include<chrono>
#include<unordered_set>
#include<iostream>
#include<cassert>

using namespace std;
using namespace std::chrono;

template <class _Value, class _Hash, class _Pred, class _Alloc>
bool
complex_perm(const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
		     const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
{
	typedef typename unordered_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
	typedef pair<const_iterator, const_iterator> _EqRng;
	for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
	{
		_EqRng __xeq = __x.equal_range(*__i);
		_EqRng __yeq = __y.equal_range(*__i);
		if (_VSTD::distance(__xeq.first, __xeq.second) !=
			_VSTD::distance(__yeq.first, __yeq.second) ||
			!_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
		return false;
		__i = __xeq.second;
	}
	return true;
}

void a ()
{
	unordered_multiset<int> u1;
	unordered_multiset<int> u2;
	for (unsigned i = 0; i < 1000 * 1000; ++i)
	{
		u1.insert(i);
		u2.insert(i);
	}
	for (unsigned i = 0; i < 1000 * 10; ++i)
	{
		u1.insert(i % 100);
		u2.insert(i % 100);
	}
	
	high_resolution_clock::time_point t1 = high_resolution_clock::now();
	
	assert(is_permutation(u1.begin(), u1.end(), u2.begin()));
	
	high_resolution_clock::time_point t2 = high_resolution_clock::now();
	cout << duration_cast<milliseconds>( t2 - t1 ).count() << endl;
}

void b ()
{
	unordered_multiset<int> u1;
	unordered_multiset<int> u2;
	for (unsigned i = 0; i < 1000 * 1000; ++i)
	{
		u1.insert(i);
		u2.insert(i);
	}
	for (unsigned i = 0; i < 1000 * 10; ++i)
	{
		u1.insert(i % 100);
		u2.insert(i % 100);
	}
	
	high_resolution_clock::time_point t1 = high_resolution_clock::now();
	
	assert(complex_perm(u1, u2));
	
	high_resolution_clock::time_point t2 = high_resolution_clock::now();
	cout << duration_cast<milliseconds>( t2 - t1 ).count() << endl;
}

int main()
{
	a();
	b();
}