2.cpp

/*************************************************************************
	> File Name: 2.cpp
	> Author: Louis1992
	> Mail: zhenchaogan@gmail.com
	> Blog: http://gzc.github.io
	> Created Time: Mon Nov 9 08:30:19 2015
 ************************************************************************/
#include<iostream>
using namespace std;

struct ListNode {
 int v;
 ListNode *next;
 ListNode(int _v):v(_v){}
};

ListNode* kthtoLast(ListNode *head, int k) {
 ListNode *fast(head);
 while(k--) fast = fast->next;
 while(fast) {
 head = head->next;
 fast = fast->next;
 }
 return head;
}

int main() {
 
 ListNode *l1 = new ListNode(1);
 ListNode *l2 = new ListNode(2);
 ListNode *l3 = new ListNode(3);
 l1->next = l2;
 l2->next = l3;
 cout << (kthtoLast(l1, 2))->v << endl;
 return 0;
}