suffix-tree

Accessing the first Character of a String with no Characters

▼魔方 西西 提交于 2020-01-24 11:08:05
问题 I am implementing a suffix trie in C++. The implementation of the Trie contructor can be seen below. #include <iostream> #include <cstring> #include "Trie.hpp" using namespace std; Trie::Trie(string T){ T += "#"; //terminating character this->T = T; nodes.reserve(T.length() * (T.length() + 1) / 2); //The number of nodes is bounded above by n(n+1)/2. The reserve prevents reallocation (http://stackoverflow.com/questions/41557421/vectors-and-pointers/41557463) vector<string> suffix; //vector of

Longest palindromic substring and suffix trie

本小妞迷上赌 提交于 2020-01-02 12:46:54
问题 I was Googling about a rather well-known problem, namely: the longest palindromic substring I have found links that recommend suffix tries as a good solution to the problem. Example SO and Algos The approach is (as I understand it) e.g. for a string S create Sr (which is S reversed) and then create a generalized suffix trie. Then find the longest common sustring of S and Sr which is the path from the root to the deepest node that belongs both to S and Sr . So the solution using the suffix

Longest palindromic substring and suffix trie

℡╲_俬逩灬. 提交于 2020-01-02 12:46:30
问题 I was Googling about a rather well-known problem, namely: the longest palindromic substring I have found links that recommend suffix tries as a good solution to the problem. Example SO and Algos The approach is (as I understand it) e.g. for a string S create Sr (which is S reversed) and then create a generalized suffix trie. Then find the longest common sustring of S and Sr which is the path from the root to the deepest node that belongs both to S and Sr . So the solution using the suffix

Suffix tree in Matlab

不想你离开。 提交于 2019-12-25 04:15:34
问题 I am finding longest substring in text T, such that it is a prefix of string S. I have made algorithm using suffix tree which provides less complex solution, but since Matlab doesn't use pointers or any other reference, I am stuck at the implementation. Could somebody please suggest some solution or some alternate way to this problem, possible in Matlab. 回答1: Here are a few suggestions for using "pointers" in Matlab: You can simply use cell array indexes as pointers, to reference cell array

Maximum and minimum number of edges in a suffix tree

天涯浪子 提交于 2019-12-24 03:51:15
问题 What are the maximum and minimum number of edges in a suffix tree? I know the maximum is 2m-1, but I don't understand why that is so. 回答1: First, about the maximum number of edges: It's quite easy to understand if you think of the edges as coming in two flavours: Edges that lead to a leaf node, and edges that lead to an inner node. In the following, I'll assume that the string the suffix tree is constructed for is N characters in length. About the edges leading to leaves . There must be

Ukkonen suffix tree: procedure 'canonize' unclear

99封情书 提交于 2019-12-23 13:22:47
问题 How does the 'canonize' function (given below, from Ukkonen's paper) work, and in particular, when is the while loop finished? I think the value of p' - k' will always remain less than that of p - k. Am I right or wrong? procedure canonize(s, (k, p)): 1. if p < k then return (s, k) 2. else 3. find the tk–transition g'(s, (k', p')) = s' from s; 4. while p' − k' <= p − k do 5. k = k + p' − k' + 1; 6. s = s'; 7. if k <= p then find the tk–transition g'(s, (k', p')) = s' from s; 8. return (s, k).

Longest maximum repeating substring

六眼飞鱼酱① 提交于 2019-12-22 18:26:43
问题 A substring can be of length 1,2,3... The question that I was trying to solve involved finding the substring that occurred the maximum number of times. So it basically broke down to finding the character having the maximum frequency. However, I found out that I can find the longest repeating substring using suffix tree in O(n). But, suffix tree returns the substring keeping the length as a priority. I wanted to find the substring which occurs the most number of times, and out of those

Understanding Ukkonen's algorithm for suffix trees [duplicate]

左心房为你撑大大i 提交于 2019-12-18 10:35:08
问题 This question already has answers here : Ukkonen's suffix tree algorithm in plain English (7 answers) Closed 6 years ago . I'm doing some work with Ukkonen's algorithm for building suffix trees, but I'm not understanding some parts of the author's explanation for it's linear-time complexity. I have learned the algorithm and have coded it, but the paper which I'm using as the main source of information (linked bellow) is kinda confusing at some parts so it's not really clear for me why the

Maximum and minimum number of nodes in a suffix tree [closed]

我只是一个虾纸丫 提交于 2019-12-18 03:34:34
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 7 years ago . What are the maximum and minimum number of nodes in a suffix tree? And how can I prove it? 回答1: Assuming an input text of N characters in length, the minimum number of nodes, including the root node and all leaf nodes, is N+1 , the maximum number of nodes, including the root and leaves, is 2N-1 . Proof of

Match and replace emoticons in string - what is the most efficient way?

狂风中的少年 提交于 2019-12-17 20:55:41
问题 Wikipedia defines a lot of possible emoticons people can use. I want to match this list to words in a string. I now have this: $string = "Lorem ipsum :-) dolor :-| samet"; $emoticons = array( '[HAPPY]' => array(' :-) ', ' :) ', ' :o) '), //etc... '[SAD]' => array(' :-( ', ' :( ', ' :-| ') ); foreach ($emoticons as $emotion => $icons) { $string = str_replace($icons, " $emotion ", $string); } echo $string; Output: Lorem ipsum [HAPPY] dolor [SAD] samet so in principle this works. However, I have