Questions tagged [fastest-algorithm]
Fastest-algorithm competitions are won by the answer with the smallest asymptotic time complexity. For challenges based on actual runtime, use [fastest-code] instead.
22
votes
23answers
3k views
Upside-Down Pyramid Addition…REVERSED!
Upside-Down Pyramid Addition is the process of taking a list of numbers and consecutively adding them together until you reach one number.
When given the numbers ...
3
votes
0answers
126 views
Minimum cost of solving the Eni-Puzzle
You're tasked with writing an algorithm to efficiently estimate cost of solving an Eni-Puzzle from a scrambled state as follows:
You're given m lists of containing n elements each(representing the ...
6
votes
2answers
284 views
Buy the most appropriate items
A store is having a big sale.
If your price reaches $199 or more, you can reduce it by $100.
You can buy each product only once.
Here's an example list of products: (in order to simplify, the names of ...
3
votes
0answers
92 views
determine if the circle is boxed in [closed]
Pretty simple challenge here. Who can make the fastest algorithm (lowest time complexity) to determine whether or not the circle is "boxed in" given the following setup?
Input: Your program receives ...
4
votes
1answer
426 views
Meeting splitter
Introduction
Large meetings waste working time. Our aim is to split a large meeting into a number of smaller meetings, so the average number topics that a person discusses is minimized but every ...
-4
votes
2answers
220 views
Fastest way to perform the equivalent of an if-statement in x86 assembly
The task is simple: Create an if-statement from scratch in x86 assembly that runs in as few clock-cycles as possible.
Must be x86 assembly.
Can't use any of the conditional jump/branch instructions (...
2
votes
1answer
253 views
Two Dimensional Waterflow problem [closed]
The one dimensional twitter waterflow problem is this:
You are given an array that represents a hill in the sense that the ith entry is the height of the ith location of the hill. When it rains, ...
1
vote
0answers
162 views
3-inverter with two NOT gates [closed]
Introduction
I recently came across an oral exam where the candidates were asked to find a logical circuit than can negate 3 inputs A,B,C using only two NOT gates.
...
5
votes
1answer
343 views
Find elements in an array computing a given function value
Problem Description
Given:
a function \$f(a, b, c, d, e) = \frac{a \times b}c + \frac de\$
an array \$x = [x_1, x_2, x_3, x_4, ..., x_n]\$ of non-distinct integers
a target value \$k\$
What is the ...
2
votes
2answers
398 views
Which number is bigger?
Define f(a,b) := a if b=1; a^f(a,b-1) if b>1 (Tetration, where ^ means power) for positive integers ...
-1
votes
1answer
204 views
Find the longest uninterrupted arc in N dimensions
See similar question for 2D case: Find the longest uninterrupted arc
The challenge here is to find the longest uninterruped great circle arc around a unit hypersphere in N dimensions, with a random ...
5
votes
3answers
340 views
Find the longest uninterrupted arc
The challenge here is to find the longest uninterruped arc around a unit circle with a random amount of points distributed in random positions around it.
Here is a diagram to assist my explanation:
...
-1
votes
3answers
318 views
Fastest to find the joint
The input is an array (or space-separated string, as you wish), zero-indexed, consisting of one strictly increasing array and one strictly decreasing array (in this order, not other vice versa), each ...
13
votes
3answers
387 views
Remove entries from array to sort it and maximize sum of elements
This challenge is from an admission test to a closed number cyber security course. Anyway it doesn't have to do with cyber security, it's just to test the students logical and coding skills.
Task
...
9
votes
3answers
842 views
Approximate floating point number with n-digit precision
We have a floating point number r between 0 and 1, and an integer p.
Find the fraction of integers with the smallest ...
3
votes
1answer
1k views
remove duplicates from array [closed]
You have given an array from which we need to remove duplicates.
Rules:
First or immediate duplicates gets removed first.
Array contains natural numbers ...
6
votes
2answers
131 views
Find the rectangle [closed]
Overview
Given a 2 dimensional array of values with a filled in rectangle, find the position and size of the rectangle. Do it in the fewest array accesses as possible.
Requirements
The ...
8
votes
0answers
366 views
Total Derangement (Difficulty Level: Hard)
The problem: Write a function which, given a cycle length n and a number of cycles m, where 'm' is within ...
5
votes
0answers
240 views
Solve a Single Player Tron Game [closed]
Solve a Tron Game
Tron is a great game, and if you haven't played it the internet has MANY online versions available.
A fun challenge is to try to write an AI that plays Tron, which is normally much ...
1
vote
1answer
113 views
Sequence avoiding near collision [closed]
Task
Find a sequence of all numbers between min and max where every number differs from every other number in the sequence by at least "d" digits.
Example of sub-sequence
For min = 0, max = 1000 ...
1
vote
0answers
103 views
Quotient in base 31 numeral system [closed]
You're given two numbers a and b in base 31 numeral system and number k with no more than 10000 decimal digits. It is known that b is divisor of a. The task is to find last k 31-based-digits of ...
9
votes
7answers
1k views
Digital River (Shortest And Fastest Solution)
This is my first question, so I hope it goes well.
Background:
It's not the rivers that you might be thinking about. The question revolves around the concept of digital rivers. A digital river is a ...
-2
votes
1answer
2k views
Find the digit occurring the most in a range of prime numbers
Find the digit which occurs the most in a range of prime numbers.
Input:
Two numbers, p and q, specifying the range; the range ...
2
votes
0answers
180 views
Num of pyramids possible with given number of bricks [closed]
I encountered this question in an interview and could not figure it out. I believe it has a dynamic programming solution but it eludes me.
Given a number of bricks, output the total number of 2d ...
-10
votes
1answer
639 views
Hard Puzzle Game Solver [closed]
There is an app called Hard Puzzle which is a game where there is a red circle, and you have to fill all of the surface area with five smaller white circles
it may seen easy, but it's harder than it ...
9
votes
7answers
812 views
Heaviest increasing subsequence
A subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. A strictly increasing subsequence is a subsequence ...
2
votes
0answers
221 views
Add or subtract numbers to find the smallest non-negative integer [closed]
Given a positive integer, n, along with n non-negative integers, write a program or function that prints or returns the smallest ...
9
votes
1answer
224 views
Number of unique outputs by substituting variables
Given a set of formulas like this:
bacb
bcab
cbba
abbc
Give an algorithm that finds the number of unique results you can get when each variable is substituted ...
7
votes
1answer
174 views
Determine sets of associatively equivalent permutations of commutative operations
There are many types of binary operations, which can be categorized by their associative properties and their commutative properties.
A binary operation () is ...
12
votes
2answers
1k views
Fastest way to compute order of magnitude in x86 assembly
The task is simple: write assembly that computes the order of magnitude of an integer using as few clock cycles as possible.
Order of magnitude is defined as log10,...
0
votes
0answers
199 views
Find the longest recurring substring [duplicate]
Given a string of no more than 255 characters, find a function that returns the longest recurring substring.
An example would be:
aabbacadeauaaabba
where the longest recurring sub-string is aabba.
...
-2
votes
2answers
869 views
Find Anagrams in the Dictionary [closed]
This a code challenge. The winner will be the person to provide the most efficient implementation of the solution in terms of algorithmic complexity.
Using the dictionary found in '/usr/share/dict' (...
9
votes
2answers
1k views
A fastest algorithm optimization challenge
This is my first experiment with an asymptotic complexity challenge although I am happy with answers entirely in code as long as they come with an explanation of their time complexity.
I have the ...
5
votes
6answers
5k views
Determine the move in which a LOGO turtle crosses a point that it has already visited [closed]
Situation:
A turtle starts at (0, 0) on a cartesian graph.
We have a non-empty zero-indexed "moves" list that contains numbers.
Each number represents the distance moved.
The first number is the ...
6
votes
9answers
5k views
Same word when missing letters [closed]
Idea
From a given word dictionary (containing only plain letters, i.e: no accent or other special chars), with a given fixed word length, find every same when a given number letters are missing.
For ...
5
votes
5answers
853 views
Mr. Moneybag's Money Piles
Mr. Moneybags is a very rich man. He has an assistant Mr. Perfect, who one day, got very mad, and shredded some of Mr. Moneybag’s $100 bills! Mr. Moneybags decided to punish Mr. Perfect.
Mr. ...
2
votes
1answer
669 views
Racketeer Taxi Driver
The Scenario
You are a taxi driver in your city. You picked up a passenger from the airport and he told you the place he'd like to go.
To earn more money, you need to drive as much as you can. ...
5
votes
3answers
260 views
Autoscale complex function
Context: We are working on a complex image drawing program to produce mugs, t-shirts, and so on. Here is an example of such function
However, we are facing the following problem: Random generated ...
6
votes
7answers
3k views
Count the Zeros
For a given n, count the total number of zeros in the decimal representation of the positive integers less than or equal to n. For instance, there are 11 zeros in the decimal representations of the ...
15
votes
16answers
28k views
Array Merge without Duplicates
I recently saw this Javascript code on StackOverflow for merging two arrays, and removing duplicates:
...
9
votes
7answers
2k views
Count the number of cyclic words in an input
Cyclic Words
Problem Statement
We can think of a cyclic word as a word written in a circle. To
represent a cyclic word, we choose an arbitrary starting position and
read the characters in ...
1
vote
4answers
705 views
Tricky Median Question
Given n points, choose a point in the given list such that the sum of distances to this point is minimum ,compared to all others.
Distance is measured in the following manner.
For a point (x,y) all ...
8
votes
6answers
2k views
Code-Challenge:The Nearest Prime
Challenge
In this task you would be given an
integer N you have to output the
nearest prime to the integer.
If the number is prime itself output the number.
The input N is given in a single ...
5
votes
4answers
661 views
Fastest algorithm for decomposing a perfect power
A perfect power is a positive integer that's equal to one positive integer, to the power of another positive integer (e.g. ab is a perfect power). Note that trivial solutions (e.g. b=1) are excluded; ...
16
votes
6answers
6k views
Count number of hefty decimals between 2 numbers
Let's say we have a non-negative integer that is "hefty" (that is, "heavy") if its average digit value is greater than 7.
The number 6959 is "hefty" because:
(6 + 9 + 5 + 9) / 4 = 7.5
The number ...
12
votes
4answers
4k views
Free a Binary Tree
So before you read some basic computer science concepts.
A binary tree is a dynamically allocated structure (usually used for ordered storage).
Because of its nature traversal of binary trees is ...
