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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <algorithm>
// template<BidirectionalIterator Iter>
// requires ShuffleIterator<Iter>
// && LessThanComparable<Iter::value_type>
// bool
// next_permutation(Iter first, Iter last);
#include <algorithm>
#include <cassert>
#include "../../iterators.h"
#include <cstdio>
int factorial(int x)
{
int r = 1;
for (; x; --x)
r *= x;
return r;
}
template <class Iter>
void
test()
{
int ia[] = {1, 2, 3, 4, 5, 6};
const int sa = sizeof(ia)/sizeof(ia[0]);
int prev[sa];
for (int e = 0; e <= sa; ++e)
{
int count = 0;
bool x;
do
{
std::copy(ia, ia+e, prev);
x = std::next_permutation(Iter(ia), Iter(ia+e));
if (e > 1)
{
if (x)
assert(std::lexicographical_compare(prev, prev+e, ia, ia+e));
else
assert(std::lexicographical_compare(ia, ia+e, prev, prev+e));
}
++count;
} while (x);
assert(count == factorial(e));
}
}
int main()
{
test<bidirectional_iterator<int*> >();
test<random_access_iterator<int*> >();
test<int*>();
}
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