Thrust库的使用 - radix sort的具体实现 写作sort by key

https://thrust.github.io/doc/group__sorting.html

https://devtalk.nvidia.com/default/topic/951795/fastest-sorting-algorithm-on-gpu-currently/

Precondition

The range [keys_first, keys_last)) shall not overlap the range [values_first, values_first + (keys_last - keys_first)).

The following code snippet demonstrates how to use sort_by_key to sort an array of character values using integers as sorting keys using the thrust::host execution policy for parallelization. The keys are sorted in descending order using the greater comparison operator.

#include

#include

...

const int N = 6;

int keys[N] = { 1, 4, 2, 8, 5, 7};

char values[N] = {'a', 'b', 'c', 'd', 'e', 'f'};

thrust::stable_sort_by_key(thrust::host, keys, keys + N, values, thrust::greater());

// keys is now { 8, 7, 5, 4, 2, 1}

// values is now {'d', 'f', 'e', 'b', 'c', 'a'}

See Also

http://www.sgi.com/tech/stl/sort.html

sort_by_key

stable_sort

template

void thrust::stable_sort_by_key	(	RandomAccessIterator1	keys_first,
		RandomAccessIterator1	keys_last,
		RandomAccessIterator2	values_first,
		StrictWeakOrdering	comp
	)

stable_sort_by_key performs a key-value sort. That is, stable_sort_by_key sorts the elements in [keys_first, keys_last) and [values_first, values_first + (keys_last - keys_first)) into ascending key order, meaning that if i and j are any two valid iterators in [keys_first, keys_last) such that i precedes j, and p and q are iterators in [values_first, values_first + (keys_last - keys_first))corresponding to i and j respectively, then *j is not less than *i.

As the name suggests, stable_sort_by_key is stable: it preserves the relative ordering of equivalent elements. That is, if x and y are elements in [keys_first, keys_last) such that x precedes y, and if the two elements are equivalent (neither x < y nor y < x) then a postcondition of stable_sort_by_key is that x still precedes y.

This version of stable_sort_by_key compares key objects using the function object comp.

Parameters

keys_first	The beginning of the key sequence.
keys_last	The end of the key sequence.
values_first	The beginning of the value sequence.
comp	Comparison operator.

Template Parameters

RandomAccessIterator1	is a model of Random Access Iterator, RandomAccessIterator1 is mutable, and RandomAccessIterator1's value_type is convertible to StrictWeakOrdering'sfirst_argument_type and second_argument_type.
RandomAccessIterator2	is a model of Random Access Iterator, and RandomAccessIterator2 is mutable.
StrictWeakOrdering	is a model of Strict Weak Ordering.

Precondition

The range [keys_first, keys_last)) shall not overlap the range [values_first, values_first + (keys_last - keys_first)).

The following code snippet demonstrates how to use sort_by_key to sort an array of character values using integers as sorting keys. The keys are sorted in descending order using the greater comparison operator.

#include

...

const int N = 6;

int keys[N] = { 1, 4, 2, 8, 5, 7};

char values[N] = {'a', 'b', 'c', 'd', 'e', 'f'};

thrust::stable_sort_by_key(keys, keys + N, values, thrust::greater());

// keys is now { 8, 7, 5, 4, 2, 1}

// values is now {'d', 'f', 'e', 'b', 'c', 'a'}

See Also

http://www.sgi.com/tech/stl/sort.html

sort_by_key

stable_sort

---

Generated on Mon Mar 2 2015 13:21:30 for thrust by    1.8.6