算法学习五---输出链表中倒数第k个结点

题目：

输入一个单向链表，输出该链表中倒数第k个结点,

链表的倒数第0个结点为链表的尾指针

算法思路：定义两个指针p,qZ指向链表头，然后让q向后移k个偏移量，此时p，q相差距离为k，然后再让p，q同时向后移，直到q指向链表尾，此时p的值就是所要求的

算法伪代码

initialize 2 pointer,let them point to link's head

let q move index k

//now p is differ k with q
when q get into the end, the p's position is we want
return p's data

C++实现

//initialize 2 pointer
ChainNode<T> *p, *q;
p = q = first;

//let q move index k
for(int i = 0; i != k; ++i)
{
q = q->link;
}

//now p is differ k with q
//when q get into the end, the p's position is we want
while(q != NULL)
{
p = p->link;
q = q->link;
}

//return p's data
return p->data;