算法——找单链表中点

package com.song.algorithm;

public class FindMid {
public static class Node{
Node next;
String data;
public Node(String data){
this.data = data;
}
}

public static Node findMiddle(Node start){
Node prev;
if(start == null ){
return null;
}else{
if(start.next != null) {
prev = start.next;
}else{
return start;
}
}
Node follow = start;
while(prev.next != null){
prev = prev.next;
if(prev.next != null){
prev = prev.next;
follow = follow.next;
}else{
break;
}
}
return follow;
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Node n1 = new Node("n1");
Node n2 = new Node("n2");
Node n3 = new Node("n3");
Node n4 = new Node("n4");
//		Node n5 = new Node("n5");
//		Node n6 = new Node("n6");
n1.next = n2;
n2.next = n3;
n3.next = n4;
//		n4.next = n5;
//		n5.next = n6;
Node res = findMiddle(n1);
System.out.println(res.data);
}

}