# Description

Given a singly linked list L: L0→L1→…→Ln-1→Ln,
reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…

You must do this in-place without altering the nodes’ values.

For example,
Given {1,2,3,4}, reorder it to {1,4,2,3}.

The original problem is here.

The original code is here.

# My Solution

I solve this problem in C++, as below:

``````/*
*Reorder List
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<stack>
#include<vector>
#include<stdlib.h>
using namespace std;
/**
* struct ListNode {
*     int val;
*     ListNode *next;
*     ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
return;
return;
ListNode* node;
vector<ListNode*> vec;
int totalNum = 0;
while(node!=NULL){
vec.push_back(node);
node = node->next;
}
int size = vec.size();
for(int i=0;i<size/2;i++){
node->next = vec[size-1-i];
node = node->next;
node->next = vec[i];
node = node->next;
}
if(size%2!=0){
node->next = vec[size/2];
node = node->next;
}
node->next=NULL;
}
};
``````

# Note

To solve the problem, use a vector to save the list and reconstruct the list.