54 lines
1.3 KiB
C
54 lines
1.3 KiB
C
#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <sys/types.h>
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extern char * _argv_0;
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extern int __libc_debug;
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struct SortableArray {
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void * data;
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size_t size;
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int (*func)(const void *, const void *);
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};
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static ssize_t partition(struct SortableArray * array, ssize_t lo, ssize_t hi) {
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char pivot[array->size];
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memcpy(pivot, (char *)array->data + array->size * hi, array->size);
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ssize_t i = lo - 1;
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for (ssize_t j = lo; j <= hi; ++j) {
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uint8_t * obj_j = (uint8_t *)array->data + array->size * j;
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if (array->func(obj_j, pivot) <= 0) {
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i++;
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if (j != i) {
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uint8_t * obj_i = (uint8_t *)array->data + array->size * i;
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for (size_t x = 0; x < array->size; ++x) {
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uint8_t tmp = obj_i[x];
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obj_i[x] = obj_j[x];
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obj_j[x] = tmp;
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}
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}
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}
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}
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return i;
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}
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static void quicksort(struct SortableArray * array, ssize_t lo, ssize_t hi) {
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if (lo >= 0 && hi >= 0) {
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if (lo < hi) {
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ssize_t pivot = partition(array, lo, hi);
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quicksort(array, lo, pivot - 1);
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quicksort(array, pivot + 1, hi);
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}
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}
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}
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void qsort(void * base, size_t nmemb, size_t size, int (*compar)(const void *, const void *)) {
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if (nmemb < 2) return;
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if (!size) return;
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struct SortableArray array = {base,size,compar};
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quicksort(&array, 0, nmemb - 1);
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}
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