From 861088152f3c0f11ed2a14f4aa5ef18c6076f63b Mon Sep 17 00:00:00 2001
From: lucielle <luci@git.lunarware.tech>
Date: Fri, 15 May 2026 23:24:04 -0500
Subject: [PATCH] reimplement compare function for quicksort

---
 include/quicksort.h |  2 +-
 include/types.h     |  3 +++
 quicksort.c         | 18 +++++++++---------
 test/test.c         |  6 +++++-
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/include/quicksort.h b/include/quicksort.h
index c88d5e0..1b0c80a 100644
--- a/include/quicksort.h
+++ b/include/quicksort.h
@@ -3,6 +3,6 @@
 
 #include "types.h"
 
-int lsort_quicksort(lsort_array* array);
+int lsort_quicksort(lsort_array* array, int_function_pointer compare_function);
 
 #endif
\ No newline at end of file
diff --git a/include/types.h b/include/types.h
index 504a38f..2332f84 100644
--- a/include/types.h
+++ b/include/types.h
@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include "string.h"
 
+
 typedef struct {
     const char *buf;
     size_t len;
@@ -13,6 +14,8 @@ typedef struct {
     int key;
     void* value;
 } lsort_item;
+typedef int (*int_function_pointer)(lsort_item*, lsort_item*);
+
 
 typedef struct {
     size_t count;
diff --git a/quicksort.c b/quicksort.c
index 895e273..3994924 100644
--- a/quicksort.c
+++ b/quicksort.c
@@ -2,12 +2,12 @@
 #include "include/types.h"
 #include "include/quicksort.h"
 
-static int partition(lsort_array* array, int L, int R) {
-    int pivot = array->items[R]->key;
+static int partition(lsort_array* array, int L, int R, int_function_pointer compare_function) {
+    lsort_item* pivot = array->items[R];
     int i = L - 1;
 
     for (int j = L; j < R; j++) {
-        if (array->items[j]->key < pivot) {
+        if (compare_function(array->items[j], pivot) < 0) {
             i = i + 1;
             lsort_array_swap(array, i, j);
         }
@@ -17,20 +17,20 @@ static int partition(lsort_array* array, int L, int R) {
     return i + 1;
 }
 
-static void _quicksort(lsort_array* array, int L, int R) {
+static void _quicksort(lsort_array* array, int L, int R, int_function_pointer compare_function) {
     if (L < R) {
-        int pivotIndex = partition(array, L, R);
-        _quicksort(array, L, pivotIndex - 1);
-        _quicksort(array, pivotIndex + 1, R);
+        int pivotIndex = partition(array, L, R, compare_function);
+        _quicksort(array, L, pivotIndex - 1, compare_function);
+        _quicksort(array, pivotIndex + 1, R, compare_function);
     }
 }
 
-int lsort_quicksort(lsort_array* array) {
+int lsort_quicksort(lsort_array* array, int_function_pointer compare_function) {
     if (array->count < 1) {
         return 0;
     }
     
-    _quicksort(array, 0, (int)array->count - 1);
+    _quicksort(array, 0, (int)array->count - 1, compare_function);
     
     return check_sorted(array);
 }
\ No newline at end of file
diff --git a/test/test.c b/test/test.c
index 3627dc3..35ae83f 100644
--- a/test/test.c
+++ b/test/test.c
@@ -75,11 +75,15 @@ int test_radix_sort() {
     return return_code;
 }
 
+int test_compare_function(lsort_item* a, lsort_item* b) {
+    return a->key - b->key;
+}
+
 int test_quicksort() {
     printf("lsort_quicksort()...\n");
     
     lsort_array* array_quicksort = generate_samples(sample_count);
-    int return_code = lsort_quicksort(array_quicksort);
+    int return_code = lsort_quicksort(array_quicksort, test_compare_function);
 
     lsort_array_destroy(array_quicksort, 1);
     return return_code;