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Questions tagged [complexity]

Complexity is the analysis of how the time and space requirements of an algorithm vary according to the size of the input. Use this tag for reviews where the "Big O" is a concern.

8
votes
1answer
823 views

Regular Expression Evaluator

Task to be accomplished: Write a function that takes two strings s and p as arguments and returns a boolean denoting whether s matches p. p is a sequence of any number of the following: a-z - ...
4
votes
5answers
108 views

Find the smallest element in a sorted and rotated array [closed]

I was solving a question asked in interview by Uber. It says: Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. Find the minimum element in \$O(\log n)\$...
5
votes
1answer
179 views

Finding the upper and lower bound using binary search

I am trying to solve this InterviewBit question https://www.interviewbit.com/problems/search-for-a-range/. My code for this seems to be working properly and it does give me the correct answers on my ...
4
votes
1answer
77 views

Time(n) Complexity of Fibonacci Algorithms

It is my first use of classes in Python. I wanted to create something useful and try some new things as I learn this cool language: strategy pattern, testing with nanoseconds precision, curve/poly ...
2
votes
2answers
142 views

Program that prints star pattern

I have a program that prints the star pattern. Starr Pattern is: ...
5
votes
1answer
81 views

Phonebook using a trie

I implemented a PhoneBook utilizing a Trie data structure. Could I ask you to evaluate it? Did I apply Trie correctly for such ...
1
vote
1answer
86 views

The quicksort algorithm in Haskell

I am learning Haskell programming language mainly from this source. And there I have encouraged with "an elegant" realization of the quicksort sorting algorithm (the Quick, sort! section). Here it is: ...
7
votes
1answer
177 views

Extending the extended Stable Marriage Problem using a Python class

As soon as I saw this open source paper, I thought that the best way to replicate their code would be using a python class. After having replicated and extended the ...
-1
votes
1answer
60 views

Reverse String in Java

I've been revamping on my coding puzzles practices. What is the complexity (both time and space) for this method: ...
1
vote
1answer
88 views

Finding pairs that add up to a given sum, using recursion

I'm currently tasked with using recursion to find pairs that add up to a given sum. How would I make the function recursiveFixedSumPairs function more efficient and truncate this code? Also, what is ...
2
votes
1answer
53 views

Modelling Immerman–Szelepcsényi in Haskell

I am trying to model the proof of Immerman–Szelepcsényi Theorem with Haskell since it heavily uses non-determinism. An explanation of what the point of this is can be found here. ...
3
votes
1answer
155 views

Circuit builder that calculates resistance/current/voltage

I am somewhat new to programming. I've written a program that takes user input accepting voltages and resistors, and calculating total resistance/current/voltage in the circuit. I am looking for ways ...
0
votes
1answer
63 views

Searching for a sum of any series in array

I'm given this method, and requested to analyze what it does, and minimize its complexity (both time and space). All values are known to be larger than zero. ...
2
votes
1answer
218 views

Vertex Cover Problem Greedy Solution [closed]

As far as I understood this problem, it is a subset of vertices of Graph G, such that every edge has at least one endpoint in the subset. This problem is considered to be NP Complete. However I think ...
2
votes
0answers
132 views

MergeSort linked list implementation

I wrote a MergeSort implementation of doubly linked list, based on the MergeSort implementation of array on the textbook Algorithms 4th, which is definitely \$O(n \log n)\$. I think my linked list ...
1
vote
1answer
123 views

Implementing `components(separatedBy:)` method in Swift

On looking at the components(separatedBy separator: String) -> [String] method from the Swift Standard Library, I tried to come up with an implementation just ...
0
votes
2answers
58 views

Unbalanced Binary Search Tree insertion and search with random and sorted values

I have created this unbalanced binary search tree in C. Can anyone say this is a true approach or not? I have two scenarios for insertion and search: in the first scenario I am inserting 10000 random ...
2
votes
2answers
101 views

Substrings search (Aho-Corasick algorithm)

I have a code where the goal is to give score to strings based on how much score certain substrings are worth (including repeating substrings). The way my code (which is based on the Aho-Corasick ...
3
votes
1answer
127 views

“Counter Game” Powers of 2 Game

I have been working on this hackerrank problem: Louise and Richard have developed a numbers game. They pick a number (1 ≤ n < 264) and check to see if it is a power of 2. If it is, they divide ...
1
vote
0answers
96 views

Codility Tape Equilibrium

This question is related to this one, since it's about the same Codility exercise (Tape Equilibrium instructions): Time complexity of tape equilibirum Basically, given an integer array, the objective ...
0
votes
2answers
42 views

Incrementing specified list values, with “catch-up” [closed]

I completed a coding challenge recently in which my function was to be given two parameters: N, the number of counters to be used (numbered 1 through N) - and A, an array of integers. Iterating ...
1
vote
0answers
35 views

Mixed Duo String Generator Part 2

Mixed Duo String Generator Hello again; Previously my code was critique and I applied this feedback to form my new revised code for the Mixed Duo String Generator. In the code below I revised it to ...
1
vote
3answers
66 views

Mixed Duo String Generator 2 [duplicate]

I've create a program that finds mixed duo within a string. It removes characters from a string that do not form the first mixed duo. It does not rearrange the order of the string, it ony remove ...
1
vote
1answer
124 views

Find maximum in sorted and rotated array

This is an interview question. A sorted rotated array is a sorted array which was rotated 0 or more times. For example: [1,2,3] -> [2,3,1] ...
3
votes
2answers
63 views

Place arithmetic signs in correct order to get the number

Given a list of numbers, place signs + or - in order to get the required number. If it's possible then return ...
2
votes
1answer
55 views

O(n) Object Pool

I recently rewrote my object pool design to \$O(n)\$ complexity. I did this using a linked list, which is not native in JavaScript. It does not, unfortunately, automatically assign ...
-3
votes
1answer
42 views

Given an array of positive integers, find shortest subarray whose sum exceeds a threshold [closed]

Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0 instead. Example: Input: ...
0
votes
0answers
32 views

Find target in sorted array pivoted at some unknown point in O(log n)

You are given an array sorted in ascending order which is rotated at some pivot unknown to you beforehand. Find your target in O(log n) which means it should be a binary search. If the value does not ...
1
vote
1answer
244 views

Median of two sorted arrays JavaScript

Trying to find the median of two sorted arrays in O(log(m+n)) or better. I believe this is O(log(m+n) or O(log(m)) or O(n). ...
1
vote
1answer
77 views

Form the largest number by swapping one pair of digits

You are given a number. You are given the opportunity to swap only once to produce the largest number. My approach was to use buckets whose values were their indexes and their locations were their ...
4
votes
1answer
523 views

Time complexity of Max counters

As per the instructions are given in MaxCounters-Codility, You are given N counters, initially set to 0, and you have two possible operations on them: <...
1
vote
1answer
33 views

Time complexity of tape equilibirum

As per the instructions on this Tape Equlibrium-Codility I've written the code ...
2
votes
1answer
355 views

Swift - Finding longest binary gap of a given integer

I recently had the chance to try Codility's algorithm training, and the very first one in the list is finding the longest binary gap of a given integer. I tried to implement this in Swift, and after ...
9
votes
0answers
121 views

Seating Students (partitioning sort of)

The goal of this code is to seat students in a classroom based on a single test score. We want students to be evenly distributed across the class such that every student is positioned next to the ...
1
vote
1answer
79 views

Rearrange an array in place such that the first and last halves are interleaved

Given an array of n elements in the following format { a1, a2, a3, a4, ….., an/2, b1, b2, b3, b4, …., bn/2 }. The task is shuffle the array to {a1, b1, a2, b2, a3, b3, ……, an/2, bn/2 } without ...
0
votes
1answer
158 views

Iteratively determine the diameter of a binary tree

Can the performance of the iterative approach be improved? I find that this approach lags behind many recursive options. no recursive answers, please. Baseline recursive approach: takes 52 steps ...
2
votes
3answers
108 views

Three Numbers in Java

Given three positive numbers A, B, and C. Find the number of positive integers less than D that are divisible by either of A, B or C. Input format The 1st argument given is an Integer A. ...
0
votes
1answer
475 views

Median of two sorted arrays

The task is to find the median of two Arrays. I have an O(n) solution. Can it be written in a better time complexity? ...
1
vote
2answers
119 views

Subset Sums in Java

Given an array of integers, print sums of all subsets in it. Output should be printed in increasing order of sums. Input : arr[] = {2, 3} Output: 0 2 3 5 Input : ...
1
vote
3answers
787 views

Sort all even numbers in ascending order and then sort all odd numbers in Descending order Java

Given an array of integers (both odd and even), the task is to sort them in such a way that the first part of the array contains odd numbers sorted in descending order, rest portion contains even ...
5
votes
5answers
959 views

Sort an array of 0s, 1s and 2s in Java

Write a program to sort an array of 0's,1's and 2's in ascending order. Input: The first line contains an integer 'T' denoting the total number of test cases. In each test cases, First ...
1
vote
1answer
66 views

Finding the horse number you will get

I got this question from the interviewbit site test. There are n horses and you are the kth person in the line to ride on the horse. All the persons in the queue will go with the lowest numbered ...
2
votes
6answers
458 views

Alone in a Couple implementation in Java

In a party everyone is in couple except one. People who are in couple have same numbers. Find out the person who is not in couple. Input: The first line contains an integer \$T\$ denoting ...
5
votes
2answers
274 views

List of Ordered pairs from unordered Pair in Java

Problem statement is Write a method that can take an unordered list of airport pairs visited during a trip and return the list in order. ...
6
votes
1answer
206 views

Moore-Neighbor Tracing Algorithm

I wrote code to extract the contour of a hole, based mostly on the Moore-Neighbor Tracing algorithm. Only a. instead of finding a shape, I'm finding a "hole"; and, b. I'm looking for the (outer) ...
0
votes
1answer
156 views

Reversing the vowels in a String

Given a string, reverse only the vowels present in it and print the resulting string. Input: First line of the input file contains an integer T denoting the number of test ...
2
votes
1answer
448 views

JavaScript Determine if Number is Lucky

A challenge from Code Fights; a function that takes a number no less than 10 and that will always have an even number of digits and determines if the sum of the first half of the digits equals the sum ...
2
votes
1answer
81 views

Anagram checking implementation

Given two strings, check whether two given strings are anagram of each other or not. An anagram of a string is another string that contains same characters, only the order of characters can be ...
1
vote
1answer
84 views

Possible letter combinations of a dial pad in linear time using a recursive approach

Time complexity: I walk the initial unzipped array of keys representing the number O(N) backwards. I then do an inner walk of the proceeding array of letters *O(L^2), mapping it to every value in the ...
4
votes
1answer
1k views

2D Maze solver using recursion in Python

A company I interviewed for sent me a coding problem to solve. The problem was to find a solution to a maze, not necessarily the shortest one. The input would be like so: ...