14. Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings.

注：这题竟然连个示例都没有，说明特殊情况并不多，就是要找出所有字符串的最长公共前缀。他应该不会超过所有字符串中最短的那个，可以试着找出最短长度n，然后每个都读取和比较n个，并根据情况不断减小那个n.

19. Remove Nth Node From End of List

Given a linked list, remove the n^th 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.

注：给出一个链表，把倒数第n个元素移除。听起来很常用的技术，了解一下链表的结构，用处 ，优势，再来做这个题。

Leetcode 题目整理-4