206. Reverse Linked List

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode() {}
 *     ListNode(int val) { this.val = val; }
 *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 * }
 */
class Solution {
    public ListNode reverseList(ListNode head) {
        ListNode head2 = null;

        ListNode curr = head;
        while(curr != null){
            head2 = insertBegin(head2,curr.val);
            curr = curr.next;
        }
        //head2 = removeEnd(head2);
        return head2;
    }
    public ListNode insertBegin(ListNode head,  int x){
        ListNode temp = new ListNode(x);
        temp.next = head;
        return temp;
    }
    public ListNode removeEnd(ListNode head){
        ListNode curr = head;
        while(curr.next.next != null){
            curr = curr.next;
        }
        curr.next = null;
        return head;
    }
}