From d3e9444cbae6167952644b91029e35fe1f2ce051 Mon Sep 17 00:00:00 2001
From: Gregory Lirent <opensource@lirent.ru>
Date: Sat, 4 Jun 2022 21:59:33 +0300
Subject: [PATCH] Add list sort

---
 src/list/sort.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 src/list/sort.c

diff --git a/src/list/sort.c b/src/list/sort.c
new file mode 100644
index 0000000..b4623d9
--- /dev/null
+++ b/src/list/sort.c
@@ -0,0 +1,104 @@
+/* This software is licensed by the MIT License, see LICENSE file */
+/*                                Copyright © 2022 Gregory Lirent */
+
+#include "include.h"
+
+/*#####################################################################################################################*/
+
+static inline void lnode_swap(lnode_t* s0, lnode_t* s1) {
+    vnode_t v = s0->node;
+    vtype   t = s0->type;
+
+    s0->node = s1->node;
+    s0->type = s1->type;
+
+    s1->node = v;
+    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);
+
+    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);
+    }
+
+    return m;
+}
+
+/*#####################################################################################################################*/
+
+static void quick_sort(lnode_t *l, lnode_t *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;
+    }
+
+    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);;
+}
+
+
+void list_reverse(list_t* x) {
+    lnode_t *l = x->first;
+    lnode_t *r = x->last;
+
+    while (l != r) {
+        lnode_swap(l, r);
+        if ((r = r->prev) == l)
+            break;
+        l = l->next;
+    }
+}