suffix-array

问题 The problem statement for this problem can be found at this link - https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=24&page=show_problem&problem=660. When I first read the problem I just could not visualize how suffix array concept is applied in this question. I read the code from this link - https://yuting-zhang.github.io/uva/2016/03/22/UVa-719.html. If some one can take one small example and help me with the complete trace applying Suffix array and LCP concepts

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

问题 Here's a very simple way to build an suffix array from a string in python: def sort_offsets(a, b): return cmp(content[a:], content[b:]) content = "foobar baz foo" suffix_array.sort(cmp=sort_offsets) print suffix_array [6, 10, 4, 8, 3, 7, 11, 0, 13, 2, 12, 1, 5, 9] However, "content[a:]" makes a copy of content, which becomes very inefficient when content gets large. So i wonder if there's a way to compare the two substrings without having to copy them. I've tried to use the buffer-builtin,

问题 I have read that the Longest Common Prefix (LCP) could be used to find the number of occurrences of a pattern in a string. Specifically, you just need to create the suffix array of the text, sort it, and then instead of doing binary search to find the range so that you can figure out the number of occurrences, you simply compute the LCP for each successive entry in the suffix array. Although using binary search to find the number of occurrences of a pattern is obvious I can't figure out how

问题 How to find the sum of length of Longest Common Prefixes of all pairs of substrings of a given string. For eg answer for string "aba" is 8. |s|<=1e5. 来源： https://stackoverflow.com/questions/42912065/sum-of-lcp-of-all-pairs-of-substrings-of-a-given-string

问题 Foreword: My question is mainly an algorithmic question, so even if you are not familiar with suffix and LCP arrays you can probably help me. In this paper it is described how to efficiently use suffix and LCP arrays for string pattern matching. I understood SA and LCP work and how the algorithm's runtime can be improved from O(P*log(N)) (where P is the length of the pattern and N is length of the string) to O(P+log(N)) (Thanks to Chris Eelmaa's answer here and jogojapans answer here). I was

问题 Foreword: My question is mainly an algorithmic question, so even if you are not familiar with suffix and LCP arrays you can probably help me. In this paper it is described how to efficiently use suffix and LCP arrays for string pattern matching. I understood SA and LCP work and how the algorithm's runtime can be improved from O(P*log(N)) (where P is the length of the pattern and N is length of the string) to O(P+log(N)) (Thanks to Chris Eelmaa's answer here and jogojapans answer here). I was

问题 I am reading about the (apparently) well known problem of the longest common substring in a series of strings, and have been following these two videos which talk about how to solve the problem using suffix arrays: (note that this question doesn't require you to watch them): https://youtu.be/Ic80xQFWevc https://youtu.be/DTLjHSToxmo The first step is that we start by concatenating all the source strings into one big one, separating each with a 'unique' sentinel, where the ASCII code of each

问题 Suppose I constructed a suffix array, i.e. an array of integers giving the starting positions of all suffixes of a string in lexicographical order. Example: For a string str=abcabbca , the suffix array is: suffixArray[] = [7 3 0 4 5 1 6 2] Explanation: i Suffix LCP of str and str[i..] Length of LCP 7 a a 1 3 abbca ab 2 0 abcabbca abcabbca 8 4 bbca empty string 0 5 bca empty string 0 1 bcabbca empty string 0 6 ca empty string 0 2 cabbca empty string 0 Now with this suffixArray constructed, I

问题 I am reading about LCP arrays and their use, in conjunction with suffix arrays, in solving the "Longest common substring" problem. This video states that the sentinels used to separate individual strings must be unique, and not be contained in any of the strings themselves. Unless I am mistaken, the reason for this is so when we construct the LCP array (by comparing how many characters adjacent suffixes have in common) we don't count the sentinel value in the case where two sentinels happen