LeetCode Partition List

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

双重指针......

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution{public:ListNode *partition(ListNode *head,int x){ListNode **t1,**t2;ListNode *ans1=NULL,*ans2=NULL;bool s1,s2;if(head==NULL)return ans1;for(s1=true,s2=true;head!=NULL;head=head->next){ListNode *t=NULL;if(head->val<x){if(s1){    t=new ListNode(head->val);    t1=&t;ans1=t;s1=false;}else{    *t1=new ListNode(head->val);}t1=&((*t1)->next);}else{if(s2){    t=new ListNode(head->val);    t2=&t;ans2=t;s2=false;}else{    *t2=new ListNode(head->val);}t2=&((*t2)->next);}}if(s1)return ans2;if(s2)return ans1;*t1=ans2;return ans1;}};