Merge pull request #87 from Joshua-Lu/patch-4

更新 0142.环形链表II Java版本
This commit is contained in:
Carl Sun
2021-05-14 09:46:44 +08:00
committed by GitHub

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@ -189,33 +189,28 @@ Java
```java ```java
public class Solution { public class Solution {
public ListNode detectCycle(ListNode head) { public ListNode detectCycle(ListNode head) {
// 1.寻找相遇点
ListNode fast = head;
ListNode slow = head; ListNode slow = head;
ListNode fast = head;
while (fast != null && fast.next != null) { while (fast != null && fast.next != null) {
fast = fast.next.next;
slow = slow.next; slow = slow.next;
if (fast != slow) { fast = fast.next.next;
continue; 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;
} }
ListNode meet = fast;
// 2.寻找入口点
slow = head;
while (slow != fast) {
slow = slow.next;
fast = fast.next;
}
return fast;
} }
return null; return null;
} }
} }
``` ```
Python Python
```python ```python