Just another update

Task/Sorting-algorithms-Quicksort/C/sorting-algorithms-quicksort.c

@@ -1,29 +1,33 @@
+#include <stdio.h>
+
 void quick_sort (int *a, int n) {
+    int i, j, p, t;
     if (n < 2)
         return;
-    int p = a[n / 2];
-    int *l = a;
-    int *r = a + n - 1;
-    while (l <= r) {
-        if (*l < p) {
-            l++;
-            continue;
-        }
-        if (*r > p) {
-            r--;
-            continue; // we need to check the condition (l <= r) every time we change the value of l or r
-        }
-        int t = *l;
-        *l++ = *r;
-        *r-- = t;
+    p = a[n / 2];
+    for (i = 0, j = n - 1;; i++, j--) {
+        while (a[i] < p)
+            i++;
+        while (p < a[j])
+            j--;
+        if (i >= j)
+            break;
+        t = a[i];
+        a[i] = a[j];
+        a[j] = t;
     }
-    quick_sort(a, r - a + 1);
-    quick_sort(l, a + n - l);
+    quick_sort(a, i);
+    quick_sort(a + i, n - i);
 }
 
 int main () {
     int a[] = {4, 65, 2, -31, 0, 99, 2, 83, 782, 1};
     int n = sizeof a / sizeof a[0];
+    int i;
+    for (i = 0; i < n; i++)
+        printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
     quick_sort(a, n);
+    for (i = 0; i < n; i++)
+        printf("%d%s", a[i], i == n - 1 ? "\n" : " ");
     return 0;
 }