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.
Sol:Given n will always be valid.
Try to do this in one pass.
public ListNode removeNthFromEnd(ListNode head, int n) {
ListNode start = new ListNode(0);
ListNode first=start, second=start;
start.next = head;
// Move n nodes
for (int i=0; i<=n; i++) {
first = first.next;
}
// Move both pointers one node at a time until end of list
while(first!=null) {
first = first.next;
second = second.next;
}
// remove nth node from end
second.next = second.next.next;
return start.next;
}
No comments:
Post a Comment