segment-tree

What are the differences between segment trees, interval trees, binary indexed trees and range trees?

由 雨燕双飞 提交于 2019-12-17 06:19:19
问题 What are differences between segment trees, interval trees, binary indexed trees and range trees in terms of: Key idea/definition Applications Performance/order in higher dimensions/space consumption Please do not just give definitions. 回答1: All these data structures are used for solving different problems: Segment tree stores intervals, and optimized for " which of these intervals contains a given point " queries. Interval tree stores intervals as well, but optimized for " which of these

Update one item in segment tree

由 一曲冷凌霜 提交于 2019-12-12 03:47:55
问题 A part of a problem I'm solving involves getting the minimum in a range of an array (RMQ), so I implemented a segment tree and it works fine so far. Then I want to update one item in the original array (There are no updates with more than one) and update it in the segment tree. What I do so far is traverse the segment tree from top to bottom till I reach the leaves, but there seems to be some bug in this. Here is the update part of the code, what seems to be wrong there ? P.S. n is not a

How to code 2D segment tree?

由 守給你的承諾、 提交于 2019-12-12 00:40:03
问题 I was solving the problem http://www.spoj.com/problems/LIS2/ on spoj. I tried for days but could not come up with a solution that could pass(time wise). Then I googled and found people talking about 2D segment tree .I searched a lot but could not find a descent explanation.Is there any other solution to this problem ?? Also on topcoder i found people say this problem is similar to www.spoj.com/problems/NICEDAY .I had solved this problem way long back and that time I even did not know 1D

Wrong Answer - Unable To Find Bug - Range Minimum Query Using Segment Trees

由 社会主义新天地 提交于 2019-12-11 15:38:10
问题 I am trying to learn segment tree through https://www.topcoder.com/community/data-science/data-science-tutorials/range-minimum-query-and-lowest-common-ancestor/ After Understanding the basics of segment trees I tried to solve this question. But only one test case is passed and on the second one, I am getting tle. On further inspection comparing the two answers using filediff I found out there are wrong answers. I am unable to find any errors. Please help. this code is for creating and

Multiplication in a range

由 淺唱寂寞╮ 提交于 2019-12-11 02:54:42
问题 I have an array to 10 numbers supprse A[10] = {1,2,3,4,5,6,7,8,9,10} and I have to compute the multiplication of numbers in a particular range but not getting correct answer, I am using segment tree and dont know how to use query operation Here is my code : #include<stdio.h> #define m 1000000000 #define MAX 100010 typedef unsigned long long ull; ull a[MAX]; ull tree[4*MAX]; void build_tree(int n,int b,int e){ if(b>e)return ; else if(b==e){ tree[n] = a[b]; return ; } build_tree(n*2,b,(b+e)/2);

Segment tree - query complexity

由 大兔子大兔子 提交于 2019-12-11 02:18:54
问题 I am having problems with understanding segment tree complexity. It is clear that if you have update function which has to change only one node, its complexity will be log(n). But I have no idea why complexity of query(a,b), where (a,b) is interval that needs to be checked, is log(n). Can anyone provide me with intuitive / formal proof to understand this? 回答1: There are four cases when query the interval (x,y) FIND(R,x,y) //R is the node % Case 1 if R.first = x and R.last = y return {R} %

How can worst case complexity of quad tree O(N)?

由 穿精又带淫゛_ 提交于 2019-12-08 08:10:39
问题 As I read from sources,I learnt that worst case complexity of Quad tree is O(N) when the 2D matrix has only one dimension.I am not able to understand the reason for this. For eg. When matrix is just 1xm,we'll keep dividing it into two halves and will reach unit cell in log(m) stops.So complexity should be log(m) THANKS 回答1: There are several ways of building a quad tree. If you take a matrix of pixels, or whatever units and make a quadtree out of it, then indeed it's height will be log(n).

Segment tree java implementation [closed]

由 半城伤御伤魂 提交于 2019-12-04 10:27:44
问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . Do you know a good implementation of a (binary) segment tree in Java? 回答1: This has been implemented within the open source Layout Management SW Package project Here is a link to the sub package You might find the code useful. I have neither verified it nor run it and I cannot find the license the code is

Range update and querying in a 2D matrix

由 大兔子大兔子 提交于 2019-12-03 00:43:15
I don't have a scenario, but here goes the problem. This is one is just driving me crazy. There is a nxn boolean matrix initially all elements are 0, n <= 10^6 and given as input. Next there will be up to 10^5 queries. Each query can be either set all elements of column c to 0 or 1, or set all elements of row r to 0 or 1. There can be another type of query, printing the total number of 1's in column c or row r. I have no idea how to solve this and any help would be appreciated. Obviously a O(n) solution per query is not feasible. The idea of using a number to order the modifications is taken

How is the memory of the array of segment tree 2 * 2 ^(ceil(log(n))) - 1?

由 |▌冷眼眸甩不掉的悲伤 提交于 2019-12-02 14:57:05
The link: http://www.geeksforgeeks.org/segment-tree-set-1-sum-of-given-range/ . This is the quoted text: We start with a segment arr[0 . . . n-1]. and every time we divide the current segment into two halves(if it has not yet become a segment of length 1), and then call the same procedure on both halves, and for each such segment we store the sum in corresponding node. All levels of the constructed segment tree will be completely filled except the last level. Also, the tree will be a Full Binary Tree because we always divide segments in two halves at every level. Since the constructed tree is
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