Skip to content

Navigation Menu

Sign in
Appearance settings

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

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Commit 2f30bab

Browse files
feat: add solutions to lc problem: No.0019 (doocs#3901)
No.0019.Remove Nth Node From End of List
1 parent 66e1a30 commit 2f30bab

File tree

4 files changed

+153
-87
lines changed

4 files changed

+153
-87
lines changed

‎solution/0000-0099/0019.Remove Nth Node From End of List/README.md‎

Lines changed: 53 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -278,6 +278,38 @@ var removeNthFromEnd = function (head, n) {
278278
};
279279
```
280280

281+
#### Swift
282+
283+
````swift
284+
/**
285+
* Definition for singly-linked list.
286+
* public class ListNode {
287+
* public var val: Int
288+
* public var next: ListNode?
289+
* public init() { self.val = 0; self.next = nil; }
290+
* public init(_ val: Int) { self.val = val; self.next = nil; }
291+
* public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }
292+
* }
293+
*/
294+
class Solution {
295+
func removeNthFromEnd(_ head: ListNode?, _ n: Int) -> ListNode? {
296+
let dummy = ListNode(0)
297+
dummy.next = head
298+
var fast: ListNode? = dummy
299+
var slow: ListNode? = dummy
300+
for _ in 0..<n {
301+
fast = fast?.next
302+
}
303+
while fast?.next != nil {
304+
fast = fast?.next
305+
slow = slow?.next
306+
}
307+
slow?.next = slow?.next?.next
308+
return dummy.next
309+
}
310+
}
311+
```
312+
281313
#### Ruby
282314

283315
```rb
@@ -311,43 +343,34 @@ end
311343
#### PHP
312344

313345
```php
314-
# Definition for singly-linked list.
315-
# class ListNode {
316-
# public $val;
317-
# public $next;
318-
319-
# public function __construct($val = 0, $next = null)
320-
# {
321-
# $this->val = $val;
322-
# $this->next = $next;
323-
# }
324-
# }
325-
346+
/**
347+
* Definition for a singly-linked list.
348+
* class ListNode {
349+
* public $val = 0;
350+
* public $next = null;
351+
* function __construct($val = 0, $next = null) {
352+
* $this->val = $val;
353+
* $this->next = $next;
354+
* }
355+
* }
356+
*/
326357
class Solution {
327358
/**
328359
* @param ListNode $head
329-
* @param int $n
360+
* @param Integer $n
330361
* @return ListNode
331362
*/
332-
333363
function removeNthFromEnd($head, $n) {
334-
$dummy = new ListNode(0);
335-
$dummy->next = $head;
336-
337-
$first = $dummy;
338-
$second = $dummy;
339-
340-
for ($i = 0; $i <= $n; $i++) {
341-
$second = $second->next;
364+
$dummy = new ListNode(0, $head);
365+
$fast = $slow = $dummy;
366+
for ($i = 0; $i < $n; $i++) {
367+
$fast = $fast->next;
342368
}
343-
344-
while ($second != null) {
345-
$first = $first->next;
346-
$second = $second->next;
369+
while ($fast->next !== null) {
370+
$fast = $fast->next;
371+
$slow = $slow->next;
347372
}
348-
349-
$first->next = $first->next->next;
350-
373+
$slow->next = $slow->next->next;
351374
return $dummy->next;
352375
}
353376
}
@@ -358,3 +381,4 @@ class Solution {
358381
<!-- solution:end -->
359382

360383
<!-- problem:end -->
384+
````

‎solution/0000-0099/0019.Remove Nth Node From End of List/README_EN.md‎

Lines changed: 53 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -275,6 +275,38 @@ var removeNthFromEnd = function (head, n) {
275275
};
276276
```
277277

278+
#### Swift
279+
280+
````swift
281+
/**
282+
* Definition for singly-linked list.
283+
* public class ListNode {
284+
* public var val: Int
285+
* public var next: ListNode?
286+
* public init() { self.val = 0; self.next = nil; }
287+
* public init(_ val: Int) { self.val = val; self.next = nil; }
288+
* public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }
289+
* }
290+
*/
291+
class Solution {
292+
func removeNthFromEnd(_ head: ListNode?, _ n: Int) -> ListNode? {
293+
let dummy = ListNode(0)
294+
dummy.next = head
295+
var fast: ListNode? = dummy
296+
var slow: ListNode? = dummy
297+
for _ in 0..<n {
298+
fast = fast?.next
299+
}
300+
while fast?.next != nil {
301+
fast = fast?.next
302+
slow = slow?.next
303+
}
304+
slow?.next = slow?.next?.next
305+
return dummy.next
306+
}
307+
}
308+
```
309+
278310
#### Ruby
279311

280312
```rb
@@ -308,43 +340,34 @@ end
308340
#### PHP
309341

310342
```php
311-
# Definition for singly-linked list.
312-
# class ListNode {
313-
# public $val;
314-
# public $next;
315-
316-
# public function __construct($val = 0, $next = null)
317-
# {
318-
# $this->val = $val;
319-
# $this->next = $next;
320-
# }
321-
# }
322-
343+
/**
344+
* Definition for a singly-linked list.
345+
* class ListNode {
346+
* public $val = 0;
347+
* public $next = null;
348+
* function __construct($val = 0, $next = null) {
349+
* $this->val = $val;
350+
* $this->next = $next;
351+
* }
352+
* }
353+
*/
323354
class Solution {
324355
/**
325356
* @param ListNode $head
326-
* @param int $n
357+
* @param Integer $n
327358
* @return ListNode
328359
*/
329-
330360
function removeNthFromEnd($head, $n) {
331-
$dummy = new ListNode(0);
332-
$dummy->next = $head;
333-
334-
$first = $dummy;
335-
$second = $dummy;
336-
337-
for ($i = 0; $i <= $n; $i++) {
338-
$second = $second->next;
361+
$dummy = new ListNode(0, $head);
362+
$fast = $slow = $dummy;
363+
for ($i = 0; $i < $n; $i++) {
364+
$fast = $fast->next;
339365
}
340-
341-
while ($second != null) {
342-
$first = $first->next;
343-
$second = $second->next;
366+
while ($fast->next !== null) {
367+
$fast = $fast->next;
368+
$slow = $slow->next;
344369
}
345-
346-
$first->next = $first->next->next;
347-
370+
$slow->next = $slow->next->next;
348371
return $dummy->next;
349372
}
350373
}
@@ -355,3 +378,4 @@ class Solution {
355378
<!-- solution:end -->
356379

357380
<!-- problem:end -->
381+
````
Lines changed: 20 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -1,40 +1,31 @@
1-
# Definition for singly-linked list.
2-
# class ListNode {
3-
# public $val;
4-
# public $next;
5-
6-
# public function __construct($val = 0, $next = null)
7-
# {
8-
# $this->val = $val;
9-
# $this->next = $next;
10-
# }
11-
# }
12-
1+
/**
2+
* Definition for a singly-linked list.
3+
* class ListNode {
4+
* public $val = 0;
5+
* public $next = null;
6+
* function __construct($val = 0, $next = null) {
7+
* $this->val = $val;
8+
* $this->next = $next;
9+
* }
10+
* }
11+
*/
1312
class Solution {
1413
/**
1514
* @param ListNode $head
16-
* @param int $n
15+
* @param Integer $n
1716
* @return ListNode
1817
*/
19-
2018
function removeNthFromEnd($head, $n) {
21-
$dummy = new ListNode(0);
22-
$dummy->next = $head;
23-
24-
$first = $dummy;
25-
$second = $dummy;
26-
27-
for ($i = 0; $i <= $n; $i++) {
28-
$second = $second->next;
19+
$dummy = new ListNode(0, $head);
20+
$fast = $slow = $dummy;
21+
for ($i = 0; $i < $n; $i++) {
22+
$fast = $fast->next;
2923
}
30-
31-
while ($second != null) {
32-
$first = $first->next;
33-
$second = $second->next;
24+
while ($fast->next !== null) {
25+
$fast = $fast->next;
26+
$slow = $slow->next;
3427
}
35-
36-
$first->next = $first->next->next;
37-
28+
$slow->next = $slow->next->next;
3829
return $dummy->next;
3930
}
4031
}
Lines changed: 27 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,27 @@
1+
/**
2+
* Definition for singly-linked list.
3+
* public class ListNode {
4+
* public var val: Int
5+
* public var next: ListNode?
6+
* public init() { self.val = 0; self.next = nil; }
7+
* public init(_ val: Int) { self.val = val; self.next = nil; }
8+
* public init(_ val: Int, _ next: ListNode?) { self.val = val; self.next = next; }
9+
* }
10+
*/
11+
class Solution {
12+
func removeNthFromEnd(_ head: ListNode?, _ n: Int) -> ListNode? {
13+
let dummy = ListNode(0)
14+
dummy.next = head
15+
var fast: ListNode? = dummy
16+
var slow: ListNode? = dummy
17+
for _ in 0..<n {
18+
fast = fast?.next
19+
}
20+
while fast?.next != nil {
21+
fast = fast?.next
22+
slow = slow?.next
23+
}
24+
slow?.next = slow?.next?.next
25+
return dummy.next
26+
}
27+
}

0 commit comments

Comments
(0)

AltStyle によって変換されたページ (->オリジナル) /