algorithm

问题 I am reading about the KMP substring search algorithm and the examples I find online use an one-dimensional table to build the prefix information table. I also read the Sedgewick explanation and he used a 2-D array to build the table and explicitly states that the space complexity of KMP is O(RM) where R is the alphabet size and M the pattern size while everywhere else it is stated that the space complexity is just O(M + N) i.e. the text to process and the pattern size itself. So I am

问题 I am implementing a LZW algorithm in C++. The size of the dictionary is a user input, but the minimum is 256, so it should work with binary files. If it reaches the end of the dictionary it goes around to the index 0 and works up overwriting it from there. For example, if i put in a alice in wonderland script and compress it with a dictionary size 512 i get this dictionary. But i have a problem with decompression and the output dictionary from decompressing the compressed file looks like this

问题 I want to find the smallest sub-array that adds up to a given target. My inputs are the an input array and the target sum. I know this problem has been asked many times, but in most cases, people are trying to find every possible combination that adds up to their target or their solution does not allow duplicates. In my case, I want to find only the smallest sub-array and duplicating data from the input array is allowed. For example, given an input array of [1,4,10,20,35] and a target of 17 ,

问题 I'm interested in a fast method for "expanding bits," which can be defined as the following: Let B be a binary number with n bits, i.e. B \in {0,1}^ n Let P be the position of all 1/true bits in B , i.e. 1 << p[i] & B == 1 , and | P |= k For another given number, A \in {0,1}^ k , let Ap be the bit-expanded form of A given B , such that Ap[j] == A[j] << p[j] . The result of the "bit expansion" is Ap . A couple examples: Given B : 00 1 0 111 0, A : 0110, then Ap should be 00 0 0 110 0 Given B :

问题 I have List of boundary boxes with min max point for example: public class BoundaryVolume { public Point3D min; public Point3D max; } BoundaryVolume Box1 = new BoundaryVolume ( new Point3D (5,10,15), new Point3D (30,50,100)); BoundaryVolume Box2 = new BoundaryVolume ( new Point3D (-30,-10,-15), new Point3D (30,50,100)); BoundaryVolume Box3 = new BoundaryVolume ( new Point3D (225,-50, -15), new Point3D (1000,0 , 0)); BoundaryVolume Box4 = new BoundaryVolume ( new Point3D (0,0,0), new Point3D

问题 I'm doing a Random Forest implementation (for classification), and I have some questions regarding the tree growing algorithm mentioned in literature. When training a decision tree, there are 2 criteria to stop growing a tree: a. Stop when there are no more features left to split a node on. b. Stop when the node has all samples in it belonging to the same class. Based on that, 1. Consider growing one tree in the forest. When splitting a node of the tree, I randomly select m of the M total

问题 A and B are sets of m and n points respectively, where m<=n . I want to find a set of m unique points from B , named C , where the sum of distances between all [A(i), C(i)] pairs is the minimal. To solve this without uniqueness constraint I can just find closest points from B to each point in A : m = 5; n = 8; dim = 2; A = rand(m, dim); B = rand(n, dim); D = pdist2(A, B); [~, I] = min(D, [], 2); C2 = B(I, :); Where there may be repeated elements of B present in C . Now the first solution is

问题 I wanted to function a function that does this: const input =“hellooooloo”; const results = getRepeated(input); console.log(results) // [(2,3), (4,7), (9,10)] It returns an array of arrays of indices of the starting and ending index of consecutively repeated chars from a string. Here is my attempt, it is a O(n^2). I wonder if there is a more elegant and efficient way of achieving this const input = 'hellooooloo'; const results = getRepeated(input); // // [(2,3), (4,7), (9,10)] function

问题 Find an algorithm to recursively remove all adjacent duplicates in a given string this is the original question.I have thought of an algorithm using stacks. 1.Initialize a stack and a char_popped variable 2.Push the first char of str into the stack. 3.now iterate through the characters of string. if the top of stack matches with the character { pop the character from the stack, char_popped=character } else { if(character==char_popped) {DONT DO ANYTHING} else push the character on the stack

问题 I am currently doing some coding in the break to be fresh ready for semester 2 at university. I have encountered a CTCI problem which I am struggling to understand, I have also looked at the hints, but still am a bit clueless on how to approach it The question One Away: There are three types of edits that can be performed on strings: Insert a character, remove a character or replace a character. Given two strings write a function to check if they are one or zero edits away Sample INPUT AND