链表－ leetcode 147. Insertion Sort List

原题链接：Insertion Sort List

题解：

/** * 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) {        /*            Time Complexity:O(N)            Space Complexity:O(1)        */        if(!head || !head->next)return head;        ListNode *start=head,*tmp=head,*after=NULL;        head=head->next;        start->next=NULL;        while(head){            after=head->next;            while(tmp->next){                if(tmp->val<head->val && tmp->next->val<head->val)tmp=tmp->next;                else break;            }            if(tmp->val>head->val){                head->next=tmp;                start=head;            }            else{                head->next=tmp->next;                tmp->next=head;            }            tmp=start;            head=after;        }        return start;    }};