[LeetCode] Insert into a Cyclic Sorted List
Question:
Given a node from a cyclic linked list which has been sorted, write a function to insert a value into the list such that it remains a cyclic sorted list. The given node can be any single node in the list.
http://leetcode.com/2011/08/insert-into-a-cyclic-sorted-list.html
// Given a node from circled sorted list, find the min node.
private ListNode findMin(ListNode node)
{
while (node.next.val >= node.val)
node = node.next;
return node.next;
}
// Insert some node into a circled sorted list
// start from a smaller node. (guarantee smallnode.val <= newnode.val)
// Thus before loop the whole circle, we must can insert the new node.
private void insertFromASmallNode(ListNode smallnode, ListNode newnode)
{
// Guarantee smallnode.val <= newnode.val
while (smallnode.next.val < newnode.val)
{
smallnode= smallnode.next;
}
// Find insert place, insert newnode after smallnode;
newnode.next = smallnode.next;
smallnode.next = newnode;
}
// O(n)
public void insert(ListNode node, ListNode newnode)
{
// Assumptions...
if (node.val > newnode.val)
node = findMin(node);
insertFromASmallNode(node, newnode);
}