Commit 0cdf537

authored

Merge pull request youngyangyang04#2518 from PHJ369906/beChild-bugfix-branch

Update: 修复原Java版本报空指针异常(NullPointerException)

2 parents a8de246 + 2dce525 commit 0cdf537Copy full SHA for 0cdf537

File tree

1 file changed

+24

-18

lines changed

problems
- 0019.删除链表的倒数第N个节点.md

1 file changed

+24

-18

lines changed

`‎problems/0019.删除链表的倒数第N个节点.md‎`

Lines changed: 24 additions & 18 deletions

Original file line number	Diff line number	Diff line change
`@@ -98,27 +98,33 @@ public:`
`98`	`98`	`### Java:`
`99`	`99`
`100`	`100`	```java
`101`		`-public ListNode removeNthFromEnd(ListNode head, int n){`
`102`		`- ListNode dummyNode = new ListNode(0);`
`103`		`- dummyNode.next = head;`
`104`		`-`
`105`		`- ListNode fastIndex = dummyNode;`
`106`		`- ListNode slowIndex = dummyNode;`
	`101`	`+class Solution {`
	`102`	`+ public ListNode removeNthFromEnd(ListNode head, int n) {`
	`103`	`+ //新建一个虚拟头节点指向head`
	`104`	`+ ListNode dummyNode = new ListNode(0);`
	`105`	`+ dummyNode.next = head;`
	`106`	`+ //快慢指针指向虚拟头节点`
	`107`	`+ ListNode fastIndex = dummyNode;`
	`108`	`+ ListNode slowIndex = dummyNode;`
	`109`	`+`
	`110`	`+ // 只要快慢指针相差 n 个结点即可`
	`111`	`+ for (int i = 0; i <= n; i++) {`
	`112`	`+ fastIndex = fastIndex.next;`
	`113`	`+ }`
`107`	`114`
`108`		`- // 只要快慢指针相差 n 个结点即可`
`109`		`- for (int i = 0; i < n ; i++){`
`110`		`- fastIndex = fastIndex.next;`
`111`		`- }`
	`115`	`+ while (fastIndex != null) {`
	`116`	`+ fastIndex = fastIndex.next;`
	`117`	`+ slowIndex = slowIndex.next;`
	`118`	`+ }`
`112`	`119`
`113`		`- while (fastIndex != null){`
`114`		`- fastIndex = fastIndex.next;`
`115`		`- slowIndex = slowIndex.next;`
	`120`	`+ // 此时 slowIndex 的位置就是待删除元素的前一个位置。`
	`121`	`+ // 具体情况可自己画一个链表长度为 3 的图来模拟代码来理解`
	`122`	`+ // 检查 slowIndex.next 是否为 null,以避免空指针异常`
	`123`	`+ if (slowIndex.next != null) {`
	`124`	`+ slowIndex.next = slowIndex.next.next;`
	`125`	`+ }`
	`126`	`+ return dummyNode.next;`
`116`	`127`	`}`
`117`		`-`
`118`		`- //此时 slowIndex 的位置就是待删除元素的前一个位置。`
`119`		`- //具体情况可自己画一个链表长度为 3 的图来模拟代码来理解`
`120`		`- slowIndex.next = slowIndex.next.next;`
`121`		`- return dummyNode.next;`
`122`	`128`	`}`
`123`	`129`	```
`124`	`130`

0 commit comments

Comments

(0)

Navigation Menu

Search code, repositories, users, issues, pull requests...

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Commit 0cdf537

File tree

1 file changed

1 file changed

`‎problems/0019.删除链表的倒数第N个节点.md‎`

0 commit comments