ListNode算法

題目是給定一個連結清單：

struct ListNode
{
    int m_nKey;
    ListNode* m_pNext;
};      

public static void main(String[] args) throws Exception {

        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            int length = scanner.nextInt();
            ListNode head = new ListNode();
            for (int i = length; i > 0; i--) {
                int key = scanner.nextInt();
                ListNode newListNode = new ListNode(key, head.next);
                head.next = newListNode;
            }
            int index = scanner.nextInt();
            for (int i = 0; i < index; i++) {
                head = head.next;
            }
            System.out.println(head.value);
        }
    }

}

class ListNode {
    int value;
    ListNode next;

    ListNode() {

    }

    ListNode(int value, ListNode next) {
        this.value = value;
        this.next = next;
    }
}