blob: 216f3ac3c16a66b6d781c1d372645dff6f43993c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
// 19. Remove Nth Node From End of List
#include "leetcode.h"
/*
* given the 'head' of a linked list, remove the n'th node from the end of the
* list and return its head
*/
struct ListNode {
int val;
struct ListNode *next;
};
int get_len(struct ListNode *head) {
struct ListNode *traverse = head;
int n = 0;
while (traverse) {
traverse = traverse->next;
n++;
}
return n;
}
struct ListNode *removeNthFromEnd(struct ListNode *head, int n) {
int len = get_len(head);
if (len == 1 && n == 1)
return NULL;
if (len == n)
return head->next;
int del_idx = len - n - 1;
struct ListNode *traverse = head;
while (del_idx) {
traverse = traverse->next;
del_idx--;
}
traverse->next = traverse->next->next;
return head;
}
|