微软算法100题13 查找单向链表倒数第K个节点

package com.rui.microsoft;

public class Test13_FindKthNodeFromBack {

public static void main(String[] args) {
Node node1 = new Node(1);
Node node2 = new Node(2);
Node node3 = new Node(3);
Node node4 = new Node(4);
Node node5 = new Node(5);

node1.next = node2;
node2.next = node3;
node3.next = node4;
node4.next = node5;

Node node = Test13_FindKthNodeFromBack.getKthFromBack(node1, 3);
System.out.println(node.value);
}

public static Node getKthFromBack(Node head, int k){
Node node = head;
if(null == node)return null;
int size = 0;
while(null != node){
node = node.next;
size++;
}

int pos = size - k;
if(pos < 0) return null;

//put pointer to the head again
int i = 0;
node = head;
while(i < pos){
node = node.next;
i++;
}
return node;
}

static class Node{
int value;
Node next;
Node(int v){
this.value = v;
}
}
}