leetcode147.cpp

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* insertionSortList(ListNode* head) {
        if(head == NULL)
        	return head;
        ListNode* helper = new ListNode(0);
        ListNode* cur = head;
        ListNode* pre = helper;
        ListNode* next = NULL;
        while(cur != NULL)
        {
        	next = cur->next;
        	while(pre->next != NULL && pre->next->val < cur->val)
        		pre = pre->next;
        	cur->next = pre->next;
        	pre->next = cur;
        	pre = helper;
        	cur = next;
        }

        return helper->next;
    }
};