CodesKiller - 博客园

2017年5月20日

摘要： Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed n 阅读全文

posted @ 2017-05-20 00:56 CodesKiller 阅读(121) 评论(0) 推荐(0)

2017年4月1日

关于Dijkstra 和 Bellman-ford算法的简单理解

摘要：两个算法都是跟求图的有源最短路径有关。Dijkstra主要针对的是无负权值节点的图，而Bellman-Ford算法则是可以处理有负权值的有向图的最短路径问题。两者都用到了一个“松弛计算”的方法，也就是在遍历图的顶点和边的过程中修改距离数组的值，从而来找出最短路径。 Dijkstra算法针对无负权值的阅读全文

posted @ 2017-04-01 07:21 CodesKiller 阅读(4415) 评论(0) 推荐(1)

What is pseudopolynomial time? How does it differ from polynomial time?

摘要： To understand the difference between polynomial time and pseudopolynomial time, we need to start off by formalizing what "polynomial time" means. The 阅读全文

posted @ 2017-04-01 06:35 CodesKiller 阅读(297) 评论(0) 推荐(0)

2017年3月28日

备忘录方法与动态规划比较

摘要：动态规划算法的基本要素： 1 最优子结构性质当问题的最优解包含了其子问题的最优解时，称该问题具有最优子结构性质。2 重叠子问题性质动态规划算法对每个问题只解一次，将其解保存在一个表格中，当再次需要解此问题时，用常数时间查看一下结果。因此，用动态规划算法通常只需要多项式时间。备忘录方法：•用一个表阅读全文

posted @ 2017-03-28 07:01 CodesKiller 阅读(1261) 评论(0) 推荐(0)

2017年3月24日

285. Inorder Successor in BST

摘要： Given a binary search tree and a node in it, find the in-order successor of that node in the BST. Note: If the given node has no in-order successor in 阅读全文

posted @ 2017-03-24 11:35 CodesKiller 阅读(169) 评论(0) 推荐(0)

222. Count Complete Tree Nodes

摘要： Given a complete binary tree, count the number of nodes. Definition of a complete binary tree from Wikipedia:In a complete binary tree every level, ex 阅读全文

posted @ 2017-03-24 08:39 CodesKiller 阅读(166) 评论(0) 推荐(0)

270. Closest Binary Search Tree Value

摘要： Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target. Note: Given target value is a floati 阅读全文

posted @ 2017-03-24 07:13 CodesKiller 阅读(130) 评论(0) 推荐(0)

272. Closest Binary Search Tree Value II

摘要： Given a non-empty binary search tree and a target value, find k values in the BST that are closest to the target. Note: Given target value is a floati 阅读全文

posted @ 2017-03-24 02:57 CodesKiller 阅读(204) 评论(0) 推荐(0)

230. Kth Smallest Element in a BST

摘要： Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. Note: You may assume k is always valid, 1 ≤ k ≤ BST's 阅读全文

posted @ 2017-03-24 01:44 CodesKiller 阅读(134) 评论(0) 推荐(0)

173. Binary Search Tree Iterator

摘要： Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Calling next() will return the n 阅读全文

posted @ 2017-03-24 01:10 CodesKiller 阅读(196) 评论(0) 推荐(0)

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