mirror of
https://github.com/RGBCube/serenity
synced 2025-07-27 00:37:45 +00:00
AK: Add a basic QuickSort template implementation.
It was depressing not being able to capture anything when passing a lambda to qsort_r() so let's just have our own QuickSort. I was gonna have to do this eventually anyway. :^)
This commit is contained in:
parent
e14dd06b8c
commit
0d5e6593b2
3 changed files with 61 additions and 16 deletions
47
AK/QuickSort.h
Normal file
47
AK/QuickSort.h
Normal file
|
@ -0,0 +1,47 @@
|
|||
#pragma once
|
||||
|
||||
namespace AK {
|
||||
|
||||
template<typename IteratorType, typename LessThan>
|
||||
IteratorType partition(IteratorType first, IteratorType last, LessThan less_than)
|
||||
{
|
||||
auto pivot = last;
|
||||
auto smallest = first - 1;
|
||||
auto it = first;
|
||||
for (; it < last; ++it) {
|
||||
if (less_than(*it, *pivot)) {
|
||||
++smallest;
|
||||
swap(*it, *smallest);
|
||||
}
|
||||
}
|
||||
swap(*(smallest + 1), *last);
|
||||
return smallest + 1;
|
||||
}
|
||||
|
||||
template<typename IteratorType, typename LessThan>
|
||||
void quick_sort_impl(IteratorType begin, IteratorType first, IteratorType last, LessThan less_than)
|
||||
{
|
||||
if (first < last) {
|
||||
auto pivot = partition(first, last, less_than);
|
||||
quick_sort_impl(begin, first, pivot - 1, less_than);
|
||||
quick_sort_impl(begin, pivot + 1, last, less_than);
|
||||
}
|
||||
}
|
||||
|
||||
template<typename T>
|
||||
bool is_less_than(const T& a, const T& b)
|
||||
{
|
||||
return a < b;
|
||||
}
|
||||
|
||||
template<typename IteratorType, typename LessThan>
|
||||
void quick_sort(IteratorType begin, IteratorType end, LessThan less_than = is_less_than)
|
||||
{
|
||||
if (begin == end)
|
||||
return;
|
||||
quick_sort_impl(begin, begin, end - 1, less_than);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
using AK::quick_sort;
|
Loading…
Add table
Add a link
Reference in a new issue