2016 年 11月 29 日随笔档案 - neverlandly

2016年11月29日

Leetcode: First Unique Character in a String

摘要： Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: s = "leetcode" return 0. s = "loveleetcode", return 2. Note: You may a... 阅读全文

posted @ 2016-11-29 12:24 neverlandly 阅读(312) 评论(0) 推荐(0)

Leetcode: Lexicographical Numbers

摘要： Solution 1: Solution 2: O(N) time, O(1) space The basic idea is to find the next number to add.Take 45 for example: if the current number is 45, the n 阅读全文

posted @ 2016-11-29 11:59 neverlandly 阅读(334) 评论(0) 推荐(0)

Leetcode: Shuffle an Array

摘要： Random random = new Random(); random.nextInt(int i); 阅读全文

posted @ 2016-11-29 10:53 neverlandly 阅读(564) 评论(0) 推荐(0)

Leetcode: Ransom Note

摘要： using one array 阅读全文

posted @ 2016-11-29 06:41 neverlandly 阅读(301) 评论(0) 推荐(0)

Leetcode: Linked List Random Node

摘要： Solution 1: Reservior sampling: (wiki introduction) Reservoir sampling is a family of randomized algorithms for randomly choosing a sample of k items 阅读全文

posted @ 2016-11-29 06:19 neverlandly 阅读(515) 评论(0) 推荐(0)

Leetcode: Insert Delete GetRandom O(1) - Duplicates allowed

摘要： The idea is to add a set to the hashMap to remember all the locations of a duplicated number. 阅读全文

posted @ 2016-11-29 02:44 neverlandly 阅读(527) 评论(0) 推荐(0)

Leetcode: Insert Delete GetRandom O(1)

摘要：最先想到是用double LinkedList+Map, 没必要，arraylist+map就够了；另外取random的方法还有，rand.nextInt(int n) returns an integer in the range [0, n) java.util.Random rand = ne 阅读全文

posted @ 2016-11-29 01:27 neverlandly 阅读(535) 评论(0) 推荐(0)