serenity/AK/InsertionSort.h
Pavel Shliak 4f6f65d1f9 AK: Fix InsertionSort to respect specified bounds
Previously, it ignored 'start', sorting from the array's
beginning. This caused unintended changes and slower
performance. Fix ensures sorting stays within 'start'
and 'end' indices only.

(cherry picked from commit 356016c626546aeb51722fe9ca5bb6a769bfe762)
2024-12-08 13:24:15 -05:00

45 lines
1.3 KiB
C++

/*
* Copyright (c) 2022, Marc Luqué <marc.luque@outlook.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Concepts.h>
#include <AK/StdLibExtras.h>
namespace AK {
// Standard Insertion Sort, with `end` inclusive!
template<typename Collection, typename Comparator, typename T = decltype(declval<Collection>()[declval<int>()])>
void insertion_sort(Collection& col, ssize_t start, ssize_t end, Comparator comparator)
requires(Indexable<Collection, T>)
{
for (ssize_t i = start + 1; i <= end; ++i) {
for (ssize_t j = i; j > start && comparator(col[j], col[j - 1]); --j)
swap(col[j], col[j - 1]);
}
}
template<typename Collection, typename Comparator, typename T = decltype(declval<Collection>()[declval<int>()])>
void insertion_sort(Collection& collection, Comparator comparator)
requires(Indexable<Collection, T>)
{
if (collection.size() == 0)
return;
insertion_sort(collection, 0, collection.size() - 1, move(comparator));
}
template<typename Collection, typename T = decltype(declval<Collection>()[declval<int>()])>
void insertion_sort(Collection& collection)
requires(Indexable<Collection, T>)
{
if (collection.size() == 0)
return;
insertion_sort(collection, 0, collection.size() - 1, [](auto& a, auto& b) { return a < b; });
}
}
using AK::insertion_sort;