Remove Nth Node From End of List
Given a linked list, remove the nth node from the end of list and return its head.
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.
Given n will always be valid.
Try to do this in one pass.
The key to solve this problem is to use two pointers: pre and cur. The pre pointer moves N steps in the first place,
Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set.
get(key) – Get the value (will always be positive) of the key if the key exists in the cache, otherwise return -1.
set(key, value) – Set or insert the value if the key is not already present. When the cache reached its capacity, it should invalidate the least recently used item before inserting a new item.
The popular method to implement an LRU cache is to use a bounded Queue.
The key to for implementing an LRU is to put any recently used data at the head of the queue.
Python List is a powerful data structure that you almost need it in every program. Python List can be used to hold a collection of items which can be any type. In this post, I will use examples to describe how to use python List.
Python List Declaration¶
It is easy to create a python list object. The following code declare a List L and initialize it with 4 values.
L = [1, 2, 'Jim', ('hello, word')]
[1, 2, 'Jim', 'hello, word']
Data look up in python List¶
We can locate the elements in the List by index.