quick sort

Author: don6hao

quick_sort.py

@@ -0,0 +1,94 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+# Definition for singly-linked list.
+class ListNode:
+    def __init__(self, x):
+        self.val = x
+        self.next = None
+
+class Solution:
+    # @param head, a ListNode
+    # @return a ListNode
+    def sortList(self, head):
+        if None == head or None == head.next:
+            return head
+        pivot   = head
+        node    = head.next
+        less_list    = None
+        greater_list = None
+        equal_list   = pivot
+
+        while None != node:
+            tmp = node.next
+            if pivot.val > node.val:
+                node.next = less_list
+                less_list = node
+            elif pivot.val < node.val:
+                node.next = greater_list
+                greater_list = node
+            else:
+                equal_list.next = node
+                equal_list = node
+            node = tmp
+        #greater_list指向等于pivot的链表
+        equal_list.next = None
+        #less_list指向小于pivot的链表
+        less_list = self.sortList(less_list)
+        #greater_list指向大于pivot的链表
+        greater_list = self.sortList(greater_list)
+        less_list = self.connect(less_list, pivot, greater_list)
+
+        return less_list
+
+    def connect(self, less_list, pivot, greater_list):
+        node = pivot
+        while True:
+            if node.next == None:
+                node.next = greater_list
+                break
+            node = node.next
+
+        node = less_list
+        if less_list == None:
+            less_list = pivot
+        else:
+            while node.next != None:
+                node = node.next
+            node.next = pivot
+        return less_list
+
+if __name__ == "__main__":
+    s = Solution()
+    head = ListNode(49)
+    node_1 = ListNode(38)
+    head.next = node_1
+
+    node_2 = ListNode(65)
+    node_1.next = node_2
+
+    node_3 = ListNode(57)
+    node_2.next = node_3
+
+    node_4 = ListNode(76)
+    node_3.next = node_4
+
+    node_5 = ListNode(33)
+    node_4.next = node_5
+
+    node_6 = ListNode(27)
+    node_5.next = node_6
+
+    #node_7 = ListNode(13)
+    #node_6.next = node_7
+
+    node = head
+    while None != node:
+        print node.val
+        node = node.next
+    print '========================='
+
+    node = s.sortList(head)
+    print '#########################'
+    while None != node:
+        print node.val
+        node = node.next