All Questions
21
questions
3
votes
1
answer
350
views
Python function to find the count of digits of numerals in base n up to a given limit
This is a simple exercise to find the count of digits of all numerals in a given base up to a given limit (not including the limit), I wrote it to determine the ratio of bytes saved when the numbers ...
- 3,178
1
vote
0
answers
174
views
Applied Solution Based On Polya Enumeration Theorem
Problem
A function solution(w, h, s) that takes 3 integers and returns the number of unique, non-equivalent configurations that can be found on a grid w blocks wide, h blocks tall and s possible ...
- 489
1
vote
1
answer
570
views
Coin Flip Streaks script
I am attempting to complete the coin flip streaks problem from automate the boring stuff with python.
My code works fine but my only concern is the phrasing of the task.
Does the question want us to ...
- 19
2
votes
2
answers
172
views
Project Euler, Problem 273: finding perfect-square partitions
Problem:
Consider equations of the form: \$a^2 + b^2 = N; 0 \leq a \leq b; a, b, N \in \mathbb{N}\$.
For \$N=65\$ there are two solutions:
\$a=1, b=8\$ and \$a=4, b=7\$.
We call \$S(...
- 41
8
votes
3
answers
1k
views
Balanced centrifuge configurations
Given an input N as the size of a centrifuge, I need to find out the number of balanced configurations. The full description is here.
Centrifuge is a piece of ...
- 317
6
votes
1
answer
1k
views
Navigating over a square spiral
I recently found adventofcode, but when I solved Day 3 in Python, I noticed that my code isn't looking very nice. The challenge is about navigating a hypothetical memory laid out in a square spiral:
...
- 163
3
votes
2
answers
588
views
Time limit exceeded on finding out the GCD and LCM of a Python list
I'm doing this HackerRank problem:
Consider two sets of positive integers, \$A=\{a_0, a_1, \ldots, a_{n-1}\}\$ and \$B=\{b_0, b_1, \ldots, b_{m-1}\}\$. We say that a positive integer, \$x\$, is ...
- 493
3
votes
3
answers
1k
views
Last five non-zero digits of a factorial in base b
This HackerRank problem (based on Project Euler problem 160) says:
For any \$n\$, let \$f_b(n)\$ be the last five digits before the trailing zeroes in \$n!\$ written in base \$b\$.
For example,...
- 133
3
votes
2
answers
620
views
Zeckendorf Representation of positive integer
Zeckendorf's theorem states that all positive integers can be represented uniquely as the sum of one or more distinct Fibonacci numbers in such a way that the sum does not include any two consecutive ...
- 131
2
votes
1
answer
577
views
Generating numbers that are a product of consecutive primes
I have implemented a correct but horribly coded solution to Project Euler Problem 293.
An even positive integer N will be called admissible, if it is a power
of 2 or its distinct prime factors ...
- 31
4
votes
3
answers
303
views
Time Limit Exceeded for ETF - Euler Totient Function at Spoj
In number theory, the totient φ of a positive integer n is defined to be the number of positive integers less than or equal to n that are coprime to n.
Given an integer n (1 ≤ n ≤ 106), compute the ...
- 241
26
votes
4
answers
1k
views
Generalized Project Euler 1: A sledgehammer to crack a nut
The problem
Project Euler 1 is one of the most asked questions on site. However I wanted to solve the more general problem of division.
Multiples of a list
If we list all the natural numbers ...
- 5,725
5
votes
6
answers
9k
views
Counting pairs of relatively prime numbers
Problem from Hacker Earth:
Inverted GCD:
Given an array a of \$N\$ numbers , you have to find the number of pair of indices \$i\$ and \$j\$ that satisfy the following relation:
\$i <...
- 455
3
votes
1
answer
2k
views
Project Euler #549: Divisibility of factorials
This is the problem:
Calculate
$$\sum_{i=2}^{10^8} s(i)$$
where \$s(n)\$ is the smallest \$m\$ such that \$n\$ divides \$m!\$.
Quite mathematical, I've found a better way than brute ...
- 131
6
votes
3
answers
3k
views
Rotating an NxN matrix
I came up with the following solution for rotating an NxN matrix 90 degrees clockwise, to solve this CodeEval challenge:
Input
The first argument is a file that contains 2D N×N matrices (where ...
- 163