Update 0142.环形链表II.md

添加 0142.环形链表II.md Java版本
This commit is contained in:
Joshua
2021-05-13 23:17:10 +08:00
committed by GitHub
parent eded252643
commit 8b343ce1b3

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@ -186,6 +186,29 @@ public:
Java
```java
public class Solution {
public ListNode detectCycle(ListNode head) {
ListNode slow = head;
ListNode fast = head;
while (fast != null && fast.next != null) {
slow = slow.next;
fast = fast.next.next;
if (slow == fast) {// 有环
ListNode index1 = fast;
ListNode index2 = head;
// 两个指针,从头结点和相遇结点,各走一步,直到相遇,相遇点即为环入口
while (index1 != index2) {
index1 = index1.next;
index2 = index2.next;
}
return index1;
}
}
return null;
}
}
```
Python