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.
简单的快慢指针问题。
#includeusing namespace std;/** * 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==NULL) return NULL; ListNode * fastp = head, * slowp = head; for(int i =0;i next; if(fastp==NULL) return head->next; while(fastp->next!=NULL){ fastp = fastp ->next; slowp = slowp ->next; } slowp->next = slowp->next->next; return head; }};int main(){ return 0;}