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Merge pull request #3479 from Xinok/issue12966

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Fix Issue 12966 - Optimization for BinaryHeap
This commit is contained in:
Dmitry Olshansky 2015-07-13 01:06:54 +03:00
commit 30e4ff1717
2 changed files with 28 additions and 65 deletions
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22
std/algorithm/sorting.d
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@ -1123,7 +1123,7 @@ private void quickSortImpl(alias less, Range)(Range r, size_t depth)
{
if (depth == 0)
{
HeapSortImpl!(less, Range).heapSort(r);
HeapOps!(less, Range).heapSort(r);
return;
}
depth = depth >= depth.max / 2 ? (depth / 3) * 2 : (depth * 2) / 3;
@ -1167,8 +1167,8 @@ private void quickSortImpl(alias less, Range)(Range r, size_t depth)
}
}
// Bottom-Up Heap-Sort Implementation
private template HeapSortImpl(alias less, Range)
// Heap operations for random-access ranges
package(std) template HeapOps(alias less, Range)
{
import std.algorithm.mutation : swapAt;
@ -1185,21 +1185,27 @@ private template HeapSortImpl(alias less, Range)
if(r.length < 2) return;
// Build Heap
size_t i = r.length / 2;
while(i > 0) sift(r, --i, r.length);
buildHeap(r);
// Sort
i = r.length - 1;
size_t i = r.length - 1;
while(i > 0)
{
swapAt(r, 0, i);
sift(r, 0, i);
percolate(r, 0, i);
--i;
}
}
//template because of @@@12410@@@
void sift()(Range r, size_t parent, immutable size_t end)
void buildHeap()(Range r)
{
size_t i = r.length / 2;
while(i > 0) percolate(r, --i, r.length);
}
//template because of @@@12410@@@
void percolate()(Range r, size_t parent, immutable size_t end)
{
immutable root = parent;
size_t child = void;