From c98de126d2252fe47dc2a9094a5f9a8fa6b4b60a Mon Sep 17 00:00:00 2001 From: Charles Cabergs Date: Sun, 11 Oct 2020 15:52:52 +0200 Subject: Removing libft/minishell_test submodules, Removing subject/README/etc --- libft/src/algo/ft_qsort.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 libft/src/algo/ft_qsort.c (limited to 'libft/src/algo/ft_qsort.c') diff --git a/libft/src/algo/ft_qsort.c b/libft/src/algo/ft_qsort.c new file mode 100644 index 0000000..0c1c0f7 --- /dev/null +++ b/libft/src/algo/ft_qsort.c @@ -0,0 +1,97 @@ +/* ************************************************************************** */ +/* */ +/* ::: :::::::: */ +/* ft_qsort.c :+: :+: :+: */ +/* +:+ +:+ +:+ */ +/* By: cacharle +#+ +:+ +#+ */ +/* +#+#+#+#+#+ +#+ */ +/* Created: 2020/01/19 07:25:51 by cacharle #+# #+# */ +/* Updated: 2020/04/04 22:10:29 by charles ### ########.fr */ +/* */ +/* ************************************************************************** */ + +#include "libft_algo.h" + +/* +** \brief Helper to create a new range +** \param lo Lower bound +** \param hi Higher bound +** \return Range struct (not allocated) +*/ + +static t_ftrange ft_range_new(int lo, int hi) +{ + t_ftrange range; + + range.lo = lo; + range.hi = hi; + return (range); +} + +/* +** \brief Array partitionning, +** takes a pivot and place every element lower than it before +** and every element greater after +** \param base Partitioned array +** \param range Lower and upper bound +** \param width Single element size +** \param compar Comparison function +*/ + +static int ft_qsort_partition(void *base, t_ftrange range, + size_t width, t_ftcompar_func compar) +{ + void *pivot; + int p; + int i; + + pivot = base + (range.hi * width); + p = range.lo; + i = range.lo - 1; + while (++i < range.hi) + { + if (compar(base + (i * width), pivot) < 0) + { + ft_memswap(base + (i * width), base + (p * width), width); + p++; + } + } + ft_memswap(pivot, base + (p * width), width); + return (p); +} + +/* +** \brief Qsort recursion function +** \param base Array to sort +** \param range Lower and upper bound which define the area to sort +** \param width Single element size +** \param compar Comparision function +*/ + +static void ft_qsort_rec(void *base, t_ftrange range, + size_t width, t_ftcompar_func compar) +{ + int pivot; + + if (range.lo >= range.hi) + return ; + pivot = ft_qsort_partition(base, range, width, compar); + ft_qsort_rec(base, ft_range_new(range.lo, pivot - 1), width, compar); + ft_qsort_rec(base, ft_range_new(pivot + 1, range.hi), width, compar); +} + +/* +** \brief Sort an array using the Quick sort algorithm +** \param base Array to sort +** \param nel Number of element in the array +** \param width Size of each element +** \param compar Comparision function +*/ + +void ft_qsort(void *base, size_t nel, size_t width, + t_ftcompar_func compar) +{ + if (width == 0 || nel < 2) + return ; + ft_qsort_rec(base, ft_range_new(0, nel - 1), width, compar); +} -- cgit