题解 | #链表中环的入口结点#

package main

func EntryNodeOfLoop(pHead *ListNode) *ListNode {
	p := pHead
	q := pHead
	for p != nil && q != nil {
		p = p.Next
		q = q.Next
		if q != nil {
			q = q.Next
		}
		if p == q {
			break
		}
	}
	p = pHead
	for p != nil && q != nil {
		if p == q {
			return q
		}
		p = p.Next
		q = q.Next
	}
	return nil
}