(156)

## Descriptionsort: implement stable sorting
This CL provides stable in-place sorting by use of
bottom up merge sort with in-place merging done by
the SymMerge algorithm from P.-S. Kim and A. Kutzner.
The additional space needed for stable sorting (in the form of
stack space) is logarithmic in the inputs size n.
Number of calls to Less and Swap grow like O(n * log n) and
O(n * log n * log n):
Stable sorting random data uses significantly more calls
to Swap than the unstable quicksort implementation (5 times more
on n=100, 10 times more on n=1e4 and 23 times more on n=1e8).
The number of calls to Less is practically the same for Sort and
Stable.
Stable sorting 1 million random integers takes 5 times longer
than using Sort.
BenchmarkSortString1K 50000 328662 ns/op
BenchmarkStableString1K 50000 380231 ns/op 1.15 slower
BenchmarkSortInt1K 50000 157336 ns/op
BenchmarkStableInt1K 50000 191167 ns/op 1.22 slower
BenchmarkSortInt64K 1000 14466297 ns/op
BenchmarkStableInt64K 500 16190266 ns/op 1.12 slower
BenchmarkSort1e2 200000 64923 ns/op
BenchmarkStable1e2 50000 167128 ns/op 2.57 slower
BenchmarkSort1e4 1000 14540613 ns/op
BenchmarkStable1e4 100 58117289 ns/op 4.00 slower
BenchmarkSort1e6 5 2429631508 ns/op
BenchmarkStable1e6 1 12077036952 ns/op 4.97 slower
## Patch Set 1 ### Patch Set 2 : diff -r ccf485b509ff https://code.google.com/p/go/ ### Patch Set 3 : diff -r ccf485b509ff https://code.google.com/p/go/ ### Patch Set 4 : diff -r ccf485b509ff https://code.google.com/p/go/ ### Patch Set 5 : diff -r ca166884c853 https://code.google.com/p/go/ ### Patch Set 6 : diff -r ca166884c853 https://code.google.com/p/go/ ### Patch Set 7 : diff -r ca166884c853 https://code.google.com/p/go/ ### Patch Set 8 : diff -r 41702da0dcc4 https://code.google.com/p/go/ ### Patch Set 9 : diff -r 63b01ec901a6 https://code.google.com/p/go/ ### Patch Set 10 : diff -r 24deeb374803 https://code.google.com/p/go/ #Total comments: 6
## Patch Set 11 : diff -r 41134e67106d https://code.google.com/p/go/ ### MessagesTotal messages: 17 |

Created 8 years, 8 months ago by volker.dobler

Modified 7 years, 6 months ago

Reviewers: dfc

Base URL:

Comments: 6

This is Rietveld f62528b