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.
4
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1answer
48 views
SQL Permission Handling in WinForms
For my application, I've opted to use Integrated Security with Windows Authentication to access the SQL database. I've created AD security groups for each role and given them ...
1
vote
1answer
40 views
Calculate trapped “rain water” in structure [on hold]
Supposed my input is [1, 4, 2, 5, 1, 2, 3] . Then we can create a
structure like this:
...
4
votes
1answer
103 views
Base-2 representation using C++
I'm preparing for a test and came across this exercise. If possible, dissect this and point out any flaws in it, keeping in mind time complexity.
In base \$-2\$, Integers are represented by ...
7
votes
3answers
137 views
Finding the shortest excerpt that contains all search terms
Write a function called answer(document, searchTerms) which
returns the shortest snippet of the document, containing all of the
given search terms. The ...
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vote
2answers
87 views
Finding number of number pairs with given difference [closed]
pairs() is a function which returns the total number of combinations whose difference is k.
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5
votes
4answers
186 views
Finding the most common character in a string with a hash map
I created a method for finding the most common character in a string (using HashMap):
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0
votes
1answer
36 views
Summing sub arrays (maximal subarray)
I have this piece of code, and I want to make if the way I'm calculating the time complexity is valid:
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6
votes
1answer
93 views
Finding the count of negative sub-arrays for a given array
I want to improve my implementation for the following problem:
You are given an array of n integers. A sub-array is "Negative" if sum of all the integers in ...
2
votes
1answer
61 views
Counting occurrences of sorted elements [closed]
Forgive the hard coded test data - but I'm looking to make the inner while loop disappear, or at least simplified so this code doesn't run in \$O(n^2)\$. I've been thinking over some ideas of how to ...
4
votes
2answers
87 views
Google's Python exercise about lists very different from the given solution
Disclaimer: Although I do believe that this is somewhat a code review, I'm not sure if this kind of question applies to the site; if not, please let me know and I'll delete it promptly.
I found ...
3
votes
1answer
45 views
Prim's minimal spanning algorithm
Is there a way to speed up this code so it is \$O(n^2)\$ instead of \$O(n^3)\$? I'd appreciate if someone showed me how to do so.
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7
votes
2answers
209 views
Solving 'decent numbers' that follow specific division rules
HackerRank Problem Statement
I have to find the largest 'decent number' having N digits. A decent number has the following properties:
3, 5, or both as its ...
5
votes
4answers
265 views
Sufficient implementation of subset sum for 45 min interview
I am preparing for interviews, and have implemented a solution to this problem from Geeks for Geeks:
Given a set of non-negative integers, and a value sum, determine if there is a subset of the ...
5
votes
2answers
188 views
“Algorithmic Crush” problem hitting timeout errors
This is the HackerRank problem Algorithmic Crush:
You are given a list of size N, initialized with zeroes. You have to perform ...
0
votes
2answers
82 views
Big O notation for quicksort implementation [closed]
I am trying to find out what would be the Big O notation of a quick sort implementation I wrote. If I can get some analysis on the code, that would be great.
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10
votes
2answers
216 views
Minimum sub-array challenge
Below is my solution to finding the minimum product sub-interval. It passed 8/12 or so test cases, but the other test cases timed out if they hadn't finished within 2 seconds. When I compile this code ...
2
votes
3answers
54 views
Intersection of subset between two lists of dicts
I want to find the intersection of two lists of dicts.
Note that equality—i.e.: what is to appear in the intersection—is given by which keys they must have equal. See the ...
3
votes
1answer
82 views
Number of paths in a grid (lattice) graph
I am trying to solve a variant of the very popular question in which we find the number of distinct valid paths on a directed graph. The graph's nodes make up a m x n lattice (grid), and the edges ...
4
votes
2answers
128 views
Extracting and analyzing data from SAP
I developed a script for the company I work for in order to extract data from SAP (CJ74) and analyze the data.
One particular issue I am finding is that for any data sets which have over 1000 lines, ...
3
votes
2answers
82 views
Given bit strings, perform a bitwise addition
I'm looking for code-review, optimizations and best practices. This code is a Java adaptation of code on geeksforgeeks.org. Please verify if space complexity is \$O(n)\$ where n is number of bits, and ...
4
votes
1answer
220 views
Finding whether there exists a pair of numbers in a set having a given product
Devise an algorithm that will operate on a number x and a set of n
distinct numbers such that in \$O(n \lg n)\$ time, the algorithm indicates
whether or not there are two numbers in the set ...
2
votes
2answers
96 views
Improving the efficiency of my FizzBuzz algorithm [closed]
I worked on an exercise from codewars, which is a variation of the popular fizzbuzz game. (If the link doesn't work, you may need to reload the page.)
In this variation, I'm supposed to find the sum ...
3
votes
1answer
54 views
Spending a target sum, preferably split equally
I have a strange programming prompt. I managed to complete an algorithm to solve smaller test entries (which i'll post). One of my test cases has to complete a 200,000 int input and my algorithm isn't ...
3
votes
1answer
53 views
Acquiring indices for anagrams of an input string
I am working on an interview question from Amazon Software:
Design an algorithm to take a list of strings as well as a single input string, and return the indices of the list which are anagrams of ...
6
votes
2answers
250 views
Finding pairs of numbers within A that add up to N
I am working on an interview question from Amazon Software Interview:
Given an integer N and an array of unsorted integers A find all pairs of numbers within A which add up to N
I have a working ...
1
vote
4answers
62 views
Finding the second largest element of large input sets
I have a problem where I need to find the second maximum element of the user inputs. It's an online practice problem and I can't figure out why the server responds back with a Non-Zero Exit Code error ...
6
votes
2answers
385 views
Sum the exponents of the prime factors of a number
My goal is to find the sum of the exponents of the prime factors of an integer.
I wrote the code below with the complexities specified here (I am not 100% sure of the complexities though):
Runtime ...
4
votes
2answers
424 views
Non-recursive method for finding a ^ n
I am working on an interview question from Amazon Software. The particular question I am working on is "to write a program to find an."
Here is my recursive solution to this problem (in Java):
...
3
votes
3answers
437 views
Find the index of the element with maximum absolute deviation
I just completed a Codility test. The question presented was pretty simple but I may have over thought it.
Question:
Find the element which has the highest absolute deviation from the mean. E.g. ...
0
votes
2answers
125 views
Uva Online Judge problem 100, 3n + 1
I am having a tough time submitting this code to UVa Online judge and having it pass. I keep getting the message - Your program used more CPU time than what is allowed for this problem. That means ...
0
votes
3answers
308 views
Finding all integers in an array with odd occurrence
I am doing an interview exercise problem from here.
The problem is to find "all numbers that occurred an odd-number of times in an array".
Here is my high level psuedo code thinking:
Construct a ...
6
votes
3answers
346 views
A partition algorithm for positive integers
I have encountered the following problem that I found very interesting to solve:
Given an array of positive integers {a1, a2, ..., an} you are required
to partition the array into 3 ...
3
votes
2answers
179 views
Removing duplicates from an array
I recently wrote this JavaScript algorithm for removing duplicates from an array as part of a job interview process, but was turned down for the position after submitting the code. I didn't receive ...
3
votes
1answer
33 views
Integrate the product of four infinite series functions
I wrote the following code to integrate the product of four functions.
Two of the functions are hypergeometric functions and the other two are incomplete gamma functions. I have written each function ...
3
votes
3answers
208 views
Determining if a pair exists in a large sorted array
I'm doing practice interview questions from here. Here is the one I am currently on - if you are given a very large sorted int array, then check of there exists a ...
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vote
0answers
246 views
DP algorithm to find minimum average wait for customer-serving system
Below is the code to find the minimum average waiting time for customers at a store. I want improve the time complexity of the code. As an overview of the logic, I start from ...
3
votes
1answer
70 views
Extracting length-3 subsequences from a list
For a list li, I want to print only the values of the triplets a, b, c where ...
3
votes
3answers
320 views
Find intersection of two arrays without duplicates
A = [9, 1, 4, 2, 5] k unique integers
B = [3, 1, 8, 7, 6, 5] n unique integers
Intersection => [1, 5]
Find an algorithm that uses \$O(1)\$ space (the space used by the return variable is not ...
3
votes
1answer
97 views
Google Code jam puzzle - Welcome to Code Jam
The problem is to count all possible sub-sequences of "welcome to code jam" in a given input string (and only return the last 4 digits of the count). Here is the link to the problem for reference.
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-1
votes
1answer
150 views
Finding the distance from each array element to the nearest zero entry
I wrote a program, that gets a certain array and replaces each value in the array with the distance from it to the closest zero value.
Time complexity is 4n => O(n). (please correct me if I'm wrong, ...
4
votes
2answers
288 views
Python Find All Adjacent Subsets of Set of Coins Which Have a Tails Minority
Given a sequence of heads and tails I want to find how many significant subsequences are in this sequence where the number of heads is not less than the number of tails. I want to achieve this in ...
2
votes
1answer
112 views
10
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7answers
3k views
Calculate square of a number without multiplication
I wrote these two methods to calculate the square of a number:
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4
votes
3answers
1k views
Rotate image 90 degree clockwise
* Time complexity: O(N)
* Memory complexity: \$O(1)\$
Is my calculation of complexity correct for this code?
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1
vote
0answers
46 views
A scalable function for get boundary vertices in a graph
Given a community division I need a list of vertices that have edges in more than one community, i.e., boundary vertices.
I've tried this:
...
5
votes
4answers
1k views
Finding overlapping time intervals
You have two lists with meetings scheduling (start time, end time). Meetings in single list don't intersect. Find all intersecting meetings across the two lists.
Is my complexity \$O(N M)\$? If I ...
5
votes
4answers
289 views
Stack with a minimum
A practice interview question:
How would you design a stack which, in addition to push and pop, also has a function getMin which returns the minimum element? Push, pop and min should all operate ...
3
votes
1answer
417 views
1
vote
2answers
302 views
Codility AbsDistinct: Why is this solution not O(n)?
This is part of a series of algorithmic lessons and tests by Codility.
For copyright reasons, I cannot reproduce the question, which asks to compute the number of distinct absolute values in a given ...
6
votes
1answer
516 views
Codility MaxCounters peformance in Python capping out at 77% performance
My problem is quite similar to the question found here, except I am attempting to answer the question in Python.
Given an array of N counters, all initialized to 0, and an array ...
