Implement QuickSort

quicksort.c

@@ -0,0 +1,45 @@
+#include "include/lsort.h"
+#include "include/types.h"
+#include "include/quicksort.h"
+#include <stdio.h>
+
+typedef int (*int_function_pointer)(int, int);
+
+static int default_compare_function(int a, int b) {
+    return a - b;
+}
+
+static int partition(lsort_array_i* array, int L, int R, int_function_pointer compare_function) {
+    int pivot = array->items[R];
+    int i = L - 1;
+
+    for (int j = L; j < R; j++) {
+        if (compare_function(array->items[j], pivot) < 0) {
+            i = i + 1;
+            lsort_array_i_swap(array, i, j);
+        }
+    }
+
+    lsort_array_i_swap(array, i + 1, R);
+    return i + 1;
+}
+
+static void _quicksort(lsort_array_i* array, int L, int R, int_function_pointer compare_function) {
+    if (L < 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_i* array, int_function_pointer compare_function) {
+    if (array->count < 1) {
+        return 0;
+    }
+    
+    if (compare_function == NULL) compare_function = default_compare_function;
+    
+    _quicksort(array, 0, (int)array->count - 1, compare_function);
+    
+    return check_sorted(array) ? 1 : 0;
+}