LeetCode Reorder List

链接: https://oj.leetcode.com/problems/reorder-list/

空间复杂度为O(n),时间复杂度为 O(n)的代码:

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution{public:void reorderList(ListNode *head){vector<ListNode *> list;ListNode *tem=head;if(head==NULL)    return;while(tem){list.push_back(tem);tem=tem->next;}int i=0,j=list.size()-1;while(i+1<j){ListNode *s1=list[i];ListNode *s2=list[j];s2->next=(s1)->next;(s1)->next=s2;i++;j--;}list[j]->next=NULL;}};