/*
public class ListNode {
int val;
ListNode next = null;
ListNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public ListNode EntryNodeOfLoop(ListNode pHead) {
ListNode slow = pHead, fast = pHead;
while( fast != null && fast.next !=null){
fast = fast.next.next;
slow = slow.next;
if( slow == fast ){
slow = pHead;
while( slow != fast){
slow = slow.next;
fast = fast.next;
}
return slow;
}
}
return null;
}
}
public class ListNode {
int val;
ListNode next = null;
ListNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public ListNode EntryNodeOfLoop(ListNode pHead) {
ListNode slow = pHead, fast = pHead;
while( fast != null && fast.next !=null){
fast = fast.next.next;
slow = slow.next;
if( slow == fast ){
slow = pHead;
while( slow != fast){
slow = slow.next;
fast = fast.next;
}
return slow;
}
}
return null;
}
}