compsci-notes-spring-2024/notes/fund-prog-3/some-sorts-2024-01-31.md
2024-01-31 20:20:15 -06:00

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# Some sorts
In pseudocode, but python syntax highlighting fits decently so that's what I'm using.
## Insertion sort (for shell sort)
```py
InsertionSortForShell(array, start, gap)
for i = start + gap to len(array) - 1 # inclusive
j = i
while (j - gap >= start) and (array[j] < array[j - gap])
swap(array[j], array[j - gap])
j = j - gap
```
## Shell sort
```py
ShellSort(array, gapList)
for gap in gapList
for i = = 0 to gap - 1
InsertionSortForShell(array, i, gap)
```
## Hibbard
2<sup>k</sup> - 1 where k is 1 to p where └ k<sup>p</sup> ┐ = N
## Pratt
For a Z-tuples for (0, 0) -> (k, k) create all the cartesian pairs
```txt
(0, 0), (0, 1), (0, 2), ..., (0, k)
(1, 0), (1, 1), (1, 2), ..., (1, k)
(2, 0), (2, 1), (2, 2), ..., (2, k)
...
(k, 0), (k, 1), (k, 2), ..., (k, k)
```
## Naive gap values
N/2<sup>k</sup>, k = 1 to p where N/2<sup>p</sup> => 1
```py
for i, j in S
value = 2<sup>i</sup> * 3<sup>j</sup>
gapList.append(value)
sort(gapList)
gapValues[0 ... N]
```