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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <algorithm>
// template<RandomAccessIterator Iter>
// requires ShuffleIterator<Iter>
// && LessThanComparable<Iter::value_type>
// void
// nth_element(Iter first, Iter nth, Iter last);
#include <algorithm>
#include <cassert>
void
test_one(unsigned N, unsigned M)
{
assert(N != 0);
assert(M < N);
int* array = new int[N];
for (int i = 0; i < N; ++i)
array[i] = i;
std::random_shuffle(array, array+N);
std::nth_element(array, array+M, array+N);
assert(array[M] == M);
std::nth_element(array, array+N, array+N); // begin, end, end
delete [] array;
}
void
test(unsigned N)
{
test_one(N, 0);
test_one(N, 1);
test_one(N, 2);
test_one(N, 3);
test_one(N, N/2-1);
test_one(N, N/2);
test_one(N, N/2+1);
test_one(N, N-3);
test_one(N, N-2);
test_one(N, N-1);
}
int main()
{
int d = 0;
std::nth_element(&d, &d, &d);
assert(d == 0);
test(256);
test(257);
test(499);
test(500);
test(997);
test(1000);
test(1009);
}
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