Let us consider a special type of a binary search tree, called a cartesian tree. Recall that a binary search tree is a rooted ordered binary tree, such that for its every node x the following condition is satisfied: each node in its left subtree has…

155. Cartesian Tree time limit per test: 0.25 sec. memory limit per test: 65536 KB input: standard input output: standard output Let us consider a special type of binary search trees, called cartesian trees. Recall that a binary searchtree is a roote…

Apple Tree POJ - 2486 题目大意:一棵点带权有根树,根节点为1.从根节点出发,走k步,求能收集的最大权值和. 树形dp.复杂度可能是O(玄学),不会超过$O(nk^2)$.(反正这题不卡这个,考思想)参考 ans[i][j][0]表示i点以下共走j步,不回来,可能收集到最大的权值ans[i][j][1]表示i点以下共走j步,回来,可能收集到最大的权值 比较复杂的是,每个节点(以下称当前节点)从其子节点转移的时候,需要用一个背包: t[i][j][0]表示当前节点的前i个子节点…

E - Apple Tree POJ - 2486 Wshxzt is a lovely girl. She likes apple very much. One day HX takes her to an apple tree. There are N nodes in the tree. Each node has an amount of apples. Wshxzt starts her happy trip at one node. She can eat up all the ap…

http://baike.baidu.com/link?url=XUt5fXQ-jtFBM0UdKiGA41_NWFvdFSYwVsy4SVvCRRuEBvNkLfT9TgOtzsXvaOT9nuq_EzKJcO0gt6nyXRSLU_ 这里有详细介绍 有一道coding test的题目给你一个int n, 一串float的数,要你实时打印出当前数到这个数前n个数这n个数里最大值,没有n个数就是前面那几个数的最大值.这里就可以用cartesian tree,label记录是数的下标,p表示数值.…

前言 最近做题目,已经不止一次用到笛卡尔树了.这种数据结构极为优秀,但是构造的细节很容易出错.因此写一篇文章做一个总结. 笛卡尔树 Cartesian Tree 引入问题 有N条的长条状的矩形,宽度都为1,第i条高度为Hi,相邻的竖立在x轴上,求最大的子矩形面积. 约定 1 ≤ N ≤ 105 1 ≤ Hi ≤ 109 分析 我们只需要求出每条矩形最多可以向两边拓展的宽度,就可以算出以这个矩形高度为高的最大子矩形面积.最后我们求一个最大值即可. 下面我们还是回到之前的笛卡尔树. 概念 笛卡尔树的…

7-4 Cartesian Tree (30分)   A Cartesian tree is a binary tree constructed from a sequence of distinct numbers. The tree is heap-ordered, and an inorder traversal returns the original sequence. For example, given the sequence { 8, 15, 3, 4, 1, 5, 12, 1…

Cartesian Tree PAT-1167 一开始我使用数组进行存储,但是这样可能会导致无法开足够大的数组,因为树如果是链表状的则无法开这么大的数组(虽然结点很少). 正确的解法还是需要建树,使用指针. #include<iostream> #include<cstring> #include<string> #include<algorithm> #include<cstdio> #include<sstream> #inclu…

[题目分析] 构造一颗笛卡尔树,然后输出这棵树即可. 首先进行排序,然后用一个栈维护最右的树的节点信息,插入的时候按照第二关键字去找,找到之后插入,下面的树成为它的左子树即可. 然后插入分三种情况讨论(最下面,中间,成为了新的树根) [代码] #include <cstdio> #include <cstring> #include <iostream> #include <algorithm> using namespace std; struct nod…

链接:https://www.nowcoder.com/acm/contest/106/J 来源:牛客网 题目描述 It's universally acknowledged that there're innumerable trees in the campus of HUST. And there are many different types of trees in HUST, each of which has a number represent its type. The doc…