algorithm

问题 My problem is limited to unsigned integers of 256 bits. I have a value x , and I need to descale it by the ratio n / d , where n < d . The simple solution is of course x * n / d , but the problem is that x * n may overflow. I am looking for any arithmetic trick which may help in reaching a result as accurate as possible. Dividing each of n and d by gcd(n, d) before calculating x * n / d does not guarantee success. Is there any process (iterative or other) which i can use in order to solve

问题 I have been trying to solve Advent of Code 2020 day 13 part 2 task. I found a lot of hints talking about something called Chinese Remainder Theorem. I have tried some implementations following npm's nodejs-chinesse-remainders but this implementation seems to be quite old (2014) and also requires extra libraries for Big Int cases. How could I implement the modular multiplicative inverse ? How could I refactor the CRT algorithm define in the npm module for which I provided a link? 回答1: As a

问题 I have been trying to solve Advent of Code 2020 day 13 part 2 task. I found a lot of hints talking about something called Chinese Remainder Theorem. I have tried some implementations following npm's nodejs-chinesse-remainders but this implementation seems to be quite old (2014) and also requires extra libraries for Big Int cases. How could I implement the modular multiplicative inverse ? How could I refactor the CRT algorithm define in the npm module for which I provided a link? 回答1: As a

问题 I am solving a problem on LeetCode, but nobody has yet been able to explain my issue. The problem is as such: Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false. Each letter in the magazine string can only be used once in your ransom note. Note: You may assume that both strings contain only lowercase letters.

问题 I am solving a problem on LeetCode, but nobody has yet been able to explain my issue. The problem is as such: Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false. Each letter in the magazine string can only be used once in your ransom note. Note: You may assume that both strings contain only lowercase letters.

问题 Given a number N and a string, I need to split the string into exactly N pieces. For example, if N=3 abcd -> ["ab", "c", "d"] abcde -> ["ab", "cd", "e"] abcdef -> ["ab", "cd", "ef"] abcdefg -> ["abc", "de", "fg"] What would be the best way to achieve this (preferably in python)? My current (not working well enough) solution is chunkSize = int(ceil(len(myString) / float(numOfChunks))) chunks = [myString[i:i+chunkSize ] for i in range(0, len(myString), chunkSize )] 回答1: A generator that divides

问题 How to find the lexicographically smallest string and has unique characters that satisfies the order given in the form of a string filled with '>' and '<'.For example, answer for the string '<<<<' is 'abcde' because 'a<b<c<d<e.How to go about it? 回答1: For string length N make a graph with N+1 nodes and N directed edges, where p[i] < p[j] denotes edge from i-th to j-th node. Then perform topological sort for this graph. Make the smallest result swapping neighbor pairs that violate natural

问题 This question already has answers here : What is the complexity of retrieval/insertion in JavaScript associative arrays (dynamic object properties) in the major javascript engines? (1 answer) Is there anything that guarantees constant time for accessing a property of an object in JavaScript? (1 answer) Closed 1 year ago . I was studying some solutions to common algorithms and I ran across something that I am curious about. I tried to find the answer myself by googling and looking at some of

问题 This question already has answers here : What is the complexity of retrieval/insertion in JavaScript associative arrays (dynamic object properties) in the major javascript engines? (1 answer) Is there anything that guarantees constant time for accessing a property of an object in JavaScript? (1 answer) Closed 1 year ago . I was studying some solutions to common algorithms and I ran across something that I am curious about. I tried to find the answer myself by googling and looking at some of

问题 I'm writing an article on the n-body problem, and I'd like to be technically accurate. The code is here. And here are the comments and loops: /** * Given N bodies with mass, in a 3d space, calculate the forces of gravity to be applied to each body. * * This function is exported to JavaScript, so only takes/returns numbers and arrays. * For N bodies, pass and array of 4N values (x,y,z,mass) and expect a 3N array of forces (x,y,z) * Those forcess can be applied to the bodies mass to update the