Simple Java Solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\n/**\n * Definition for singly-linked list.\n * public class ListNode {\n *     int val;\n *     ListNode next;\n *     ListNode() {}\n *     ListNode(int val) { this.val = val; }\n *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }\n * }\n */\nclass Solution {\n    public void reorderList(ListNode head) {\n        List<ListNode> arr = new ArrayList<>();\n        ListNode node = head;\n        while(node != null) {\n            arr.add(node);\n            node = node.next;\n        }\n        node = head;\n        for(int i = 0 ; i < arr.size()/2 ; i++) {\n            ListNode ins = arr.get(arr.size()-i-1);\n            ListNode insP = arr.get(arr.size()-i-2);\n            insP.next = null;\n            ListNode rn = node.next;\n            node.next = ins;\n            ins.next = rn;\n            if(rn != null) node = rn;\n        }\n    }\n}\n```
['Java']