From 79935eb0b4eaf4c8334194c841bdd4b8621ff3b5 Mon Sep 17 00:00:00 2001
From: Gregory Lirent <opensource@lirent.ru>
Date: Sun, 5 Jun 2022 18:35:14 +0300
Subject: [PATCH] Update list sort

---
 src/list/sort.c | 74 ++++++++++++-------------------------------------
 1 file changed, 17 insertions(+), 57 deletions(-)

diff --git a/src/list/sort.c b/src/list/sort.c
index b4623d9..9162654 100644
--- a/src/list/sort.c
+++ b/src/list/sort.c
@@ -16,78 +16,38 @@ static inline void lnode_swap(lnode_t* s0, lnode_t* s1) {
     s1->type = t;
 }
 
-static inline lnode_t* mid(lnode_t* l, lnode_t *r) {
-    while (l != r) {
-        if ((r = r->prev) == l)
-            break;
-        l = l->next;
-    }
-
-    return l;
-}
-
 static inline lnode_t* pivot(lnode_t *l, lnode_t *r) {
 
-    lnode_t *m = mid(l, r);
+    lnode_t *c = l->prev;
 
-    if (lnode_compare(m, l) < 0)
-        lnode_swap(m, l);
-
-    if (lnode_compare(m, r) > 0) {
-        lnode_swap(m, r);
-
-        if (lnode_compare(m, l) < 0)
-            lnode_swap(m, l);
+    for (lnode_t* i = l; i != r; i = i->next) {
+        if (lnode_compare(i, r) < 0) {
+            c = (is_null(c)) ? l : c->next;
+            lnode_swap(c, i);
+        }
     }
 
-    return m;
+    c = (is_null(c)) ? l : c->next;
+    lnode_swap(c, r);
+
+    return c;
 }
 
-/*#####################################################################################################################*/
+static void quick_sort(lnode_t* l, lnode_t* r) {
+    lnode_t* p;
 
-static void quick_sort(lnode_t *l, lnode_t *r) {
+    if (!is_null(r) && l != r && l != r->next) {
+        p = pivot(l, r);
 
-    lnode_t *c;
-    lnode_t *m = pivot(l, r);
-    lnode_t *n = l;
-    lnode_t *p = r;
-    int      f = 0;
-
-    for (;;) {
-        while (lnode_compare(l, m) < 0) {
-            l = l->next;
-            if (p == l) /* l >= p */
-                f |= 0x01;
-        }
-
-        c = l->prev;
-
-        while (lnode_compare(r, m) > 0) {
-            r = r->prev;
-            if (n == r) /* n >= r */
-                f |= 0x02;
-            if (c == r) /* l > r */
-                f |= 0x04;
-        }
-
-        if (!(f&0x04)) { /* l <= r */
-            lnode_swap(l, r);
-            l = l->next;
-            r = r->prev;;
-        } else break;
+        quick_sort(l, p->prev);
+        quick_sort(p->next, r);
     }
-
-    if (!(f&0x02)) /* n < r */
-        quick_sort(n, r);
-    if (!(f&0x01)) /* l < p */
-        quick_sort(l, p);
 }
 
 /*#####################################################################################################################*/
 
 void list_sort(list_t* x) {
-    if (x->first != x->last)
-        return quick_sort(x->first, x->last);;
+    return quick_sort(x->first, x->last);
 }