algorithm

问题 Given a string of digits, count the number of subwords (consistent subsequences) that are anagrams of any palindrome. My attempt in Python: def ispalin(s): if len(s)%2==0: for i in s: if s.count(i)%2!=0: return False else: sum =0 for i in set(s): if s.count(i)%2==1: sum = sum+1 if sum == 1: return True else: return False return True def solution(S): # write your code in Python 3.6 count=len(S) for i in range(len(S)): for j in range(i+1,len(S)): if ispalin(S[i:j+1]): count=count+1 return count

问题 I have a lot of music and i want to rank them from least favorite to favorite (this will take many days). I would like to compare two music files at a time (2-way comparison). I saw some questions on algorithms with the fewest comparisons. But the catch is that (since it's a long process) i want to add new music to the collection and in that case i don't want to start over sorting everything (thus creating a lot more comparison steps). Which algorithm has the least amount of comparisons while

问题 I have a graph in neo4j where a node represents a city and a relationship represents roads connecting the cities. The relationships are weighted and have a property called 'distance'. I want to find the shortest (least weighted path) between two cities A and B. This is easily done using Dijkstra's algorithm. The tricky part is that I have a set of cities which are to be covered in the path from A to B. In other words, the path from A to B should cover all the waypoints, the order doesn't

问题 I have a graph in neo4j where a node represents a city and a relationship represents roads connecting the cities. The relationships are weighted and have a property called 'distance'. I want to find the shortest (least weighted path) between two cities A and B. This is easily done using Dijkstra's algorithm. The tricky part is that I have a set of cities which are to be covered in the path from A to B. In other words, the path from A to B should cover all the waypoints, the order doesn't

问题 I'm having some trouble implementing the Karatsuba algorithm. My project limits me to the following libraries: iostream, iomanip, cctype, cstring. Also, I'm limited to only using the integer built-in type and arrays/dynamic arrays to handle numbers (only unsigned integers will be input). I've built a class to handle integers of arbitrary size using dynamic arrays. I need to implement a function that multiplies big integers, and I'd like to use Karatsuba if possible. The trouble I'm running

问题 Use-case Generate a synthetic 3D scene using random points Generate two synthetic cameras Get the 2 camera 2D projections Derive the Fundamental & Essential matrices Derive rotation & translation using the Essential matrix Triangulate the 2 2D projections to result the initial 3D scene Implementation Random 3D points ( x, y, z ) are generated Camera intrinsic matrix is statically defined Rotation matrix is statically defined ( 25 deg rotation on the Z-axis ) Identity Translation Matrix ( no

问题 I can't begin to understand how to approach this problem. Can someone help me to just point me in the direction as to how I can approach it? N tasks are given and there are M workers that are available. Each worker can takes different times to complete each task. The time taken by each worker for every task is given. At any time only one task can be worked on by only one worker. But the condition is once a worker has stopped working, he can't work on any task again. I want to find out what is

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 6 years ago . Improve this question I am trying to understand what exactly Big O notation is. I understand it in the literal and practical sense by going through the answers of similar questions in SO. But what the answers don't explain and i fail to understand is the mathematical basis behind

问题 I work with data set consists about 200k objects. Every object has 4 features. I classifies them by K nearest neighbors (KNN) with euclidean metric. Process is finished during about 20 seconds. Lately I've got a reason to use custom metric. Probably it will make better results. I've implemented custom metric and KNN has become to work more than one hour. I didn't wait for finishing of it. I assumed that a reason of this issue is my metric. I replace my code by return 1 . KNN still worked more

问题 I work with data set consists about 200k objects. Every object has 4 features. I classifies them by K nearest neighbors (KNN) with euclidean metric. Process is finished during about 20 seconds. Lately I've got a reason to use custom metric. Probably it will make better results. I've implemented custom metric and KNN has become to work more than one hour. I didn't wait for finishing of it. I assumed that a reason of this issue is my metric. I replace my code by return 1 . KNN still worked more