lintcode 466. 链表节点计数

466. 链表节点计数 

计算链表中有多少个节点.

 

样例

给出 1->3->5, 返回 3.

/**
 * Definition of ListNode
 * class ListNode {
 * public:
 *     int val;
 *     ListNode *next;
 *     ListNode(int val) {
 *         this->val = val;
 *         this->next = NULL;
 *     }
 * }
 */


class Solution {
public:
    /*
     * @param head: the first node of linked list.
     * @return: An integer
     */
    int countNodes(ListNode * head) {
        // write your code here
        int count = 0;
        while (head->next) {
            count++;
            head = head->next;
        }
        return count;
    }
};