Sort list

Signed-off-by: Leo Ma <begeekmyfriend@gmail.com>

Author: begeekmyfriend

148_sort_list/Makefile

@@ -0,0 +1,2 @@
+all:
+	gcc -O2 -o test sort_list.c

148_sort_list/sort_list.c

@@ -0,0 +1,68 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct ListNode {
+    int val;
+    struct ListNode *next;
+};
+
+static void recursive(struct ListNode *dummy, struct ListNode *end)
+{
+    if (dummy == NULL || dummy->next == end) {
+        return;
+    }
+
+    struct ListNode *pivot = dummy->next;
+    struct ListNode *prev = pivot;
+    struct ListNode *p = pivot->next;
+    struct ListNode *first = NULL;
+
+    while (p != end) {
+        if (p->val >= pivot->val) {
+            if (first == NULL && p->val > pivot->val) {
+                first = prev;
+            }
+            prev = p;
+            p = p->next;
+        } else {
+            prev->next = p->next;
+            p->next = dummy->next;
+            dummy->next = p;
+            p = prev->next;
+        }
+    }
+
+    recursive(dummy, pivot);
+    recursive(first, end);
+}
+
+static struct ListNode *sortList(struct ListNode *head)
+{
+    struct ListNode dummy;
+    dummy.next = head;
+    recursive(&dummy, NULL);
+    return dummy.next;
+}
+
+int main(int argc, char **argv)
+{
+    int i, count = argc - 1;
+    struct ListNode *head = NULL, *p, *prev;
+    for (i = 0; i < count; i++) {
+        p = malloc(sizeof(*p));
+        p->val = atoi(argv[i + 1]);
+        p->next = NULL;
+        if (head == NULL) {
+            head = p;
+        } else {
+            prev->next = p;
+        }
+        prev = p;
+    }
+
+    for (p = sortList(head); p != NULL; p = p->next) {
+        printf("%d ", p->val);
+    }
+    printf("\n");
+    return 0;
+}