[Leetcode] Insertion Sort List

Well, life gets difficult pretty soon whenever the same operation on array is transferred to linked list.

First, a quick recap of insertion sort:

Start from the second element (simply a[1] head -> next -> val in array and the annoying in linked list), each time when we see a node valwith smaller than it previous node, we scan from the and find the position, which the current head node should is in Serted. Since a node may is inserted before head , we create a that new_head points to head . The insertion operation, however, is a little easier for linked list.

Now comes the code:

1 classSolution {2  Public:3listnode* Insertionsortlist (listnode*head) {4listnode* New_head =NewListNode (0);5New_head-Next =head;6listnode* pre =New_head;7listnode* cur =head;8          while(cur) {9             if(cur, next && cur, Next, Val < curval) {Ten                  while(Pre, next && pre, Next, Val < cur, nextval) OnePre = PreNext; A                 /*Insert cur, next after pre.*/ -listnode* temp = PreNext; -Pre, next = curNext; theCur next = cur, nextNext; -Pre-Next Next =temp; -                 /*Move pre back to New_head.*/ -Pre =New_head; +             } -             Elsecur = curNext; +         } Alistnode* res = New_headNext; at         DeleteNew_head; -         returnRes; -     } -};

[Leetcode] Insertion Sort List