public void reorderList(ListNode head){
	    	if(head != null && head.next != null){
	    		ListNode slow = head;
	    		ListNode fast = head;
	    		
	    		while(fast!=null && fast.next!=null&&fast.next.next!=null){
	    			slow = slow.next;
	    			fast=fast.next.next;
	    		}
	    		
	    		ListNode second = slow.next;
	    		slow.next = null;
	    		
	    		second = reverseOrder(second);
	    		
	    		ListNode list1 = head;
	    		ListNode list2 = second;
	    		
	    		while(list2!=null){
	    			ListNode temp1 = list1.next;
	    			ListNode temp2 = list2.next;
	    			
	    			list1.next = list2;
	    			list2.next = temp1;
	    			
	    			list1 = temp1;
	    			list2 = temp2;
	    		}
	    	}
	    }