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Copy pathRemoveNthNodeFromEndOfList.cpp
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Copy pathRemoveNthNodeFromEndOfList.cpp
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46 lines (38 loc) · 1 KB
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/**
Given a linked list, remove the nth node from the end of list and return its head.
For example,
Given linked list: 1->2->3->4->5, and n = 2.
After removing the second node from the end, the linked list becomes 1->2->3->5.
Note:
Given n will always be valid.
Try to do this in one pass.
*/
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
ListNode *removeNthFromEnd(ListNode *head, int n) {
if (!head) return NULL;
ListNode* slow = head;
ListNode* fast = head;
while (n-- >0) {
fast = fast->next;
}
ListNode* curr = head;
while (fast) {
fast = fast->next;
slow = curr;
curr = curr->next;
}
slow->next = curr->next;
ListNode* res = head;
if (curr == head) res = head->next;
return res;
}
};