From ed90b1bdc0017481bd48cc31728f7bd6e9bfc3f0 Mon Sep 17 00:00:00 2001
From: Jia Xu <dolremi@gmail.com>
Date: Fri, 19 Dec 2014 21:14:24 -0800
Subject: [PATCH] Correct solution for Insertion Sort List

Modify the code to pass the test of cases such as 1-> NULL or 1->1->NULL
The code has passed the test cases in leetcode
---
 C++/chapSorting.tex | 31 ++++++++++++++++++-------------
 1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/C++/chapSorting.tex b/C++/chapSorting.tex
index a1192eb5..9c1edc51 100644
--- a/C++/chapSorting.tex
+++ b/C++/chapSorting.tex
@@ -157,23 +157,28 @@ \subsubsection{代码}
 public:
     ListNode *insertionSortList(ListNode *head) {
         ListNode dummy(INT_MIN);
-        //dummy.next = head;
-
-        for (ListNode *cur = head; cur != nullptr;) {
-            auto pos = findInsertPos(&dummy, cur->val);
-            ListNode *tmp = cur->next;
-            cur->next = pos->next;
-            pos->next = cur;
-            cur = tmp;
-        }
+        dummy.next = head;
+
+        for (ListNode *p = &dummy; p->next != nullptr;) {
+        auto pos = findInsertPos(&dummy, p->next, p->next->val);
+        if(pos->next == p->next){
+            p = p->next;
+        }else{
+            ListNode *tmp = p->next->next;
+            p->next->next = pos->next;
+            pos->next = p->next;
+            p->next = tmp;
+            }
+    }
         return dummy.next;
     }
 
-    ListNode* findInsertPos(ListNode *head, int x) {
+    ListNode* findInsertPos(ListNode *head, ListNode *last, int x) {
         ListNode *pre = nullptr;
-        for (ListNode *cur = head; cur != nullptr && cur->val <= x;
-            pre = cur, cur = cur->next)
-            ;
+             
+        for (ListNode *cur = head; cur != last && cur->val <= x; cur = cur->next)
+              pre = cur;
+    
         return pre;
     }
 };