Project Euler/500: Difference between revisions
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Problem: https://projecteuler.net/problem=500 | |||
To find the smallest number with 2^n divisors: | To find the smallest number with 2^n divisors: | ||
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Build a generator to generate these numbers dynamically. | Build a generator to generate these numbers dynamically. | ||
* | * List of primes from sieve. | ||
* List of queues or sub-generators, each accessing the list of primes and an internal counter | |||
List of | |||
Ask the generator to populate up to MAX: | |||
* It will generate all primes up to MAX | |||
* It will decide the order in which to serve these up | |||
* | |||
How many primes up do we go for each column? | How many primes up do we go for each column? | ||
Latest revision as of 11:12, 14 July 2017
Problem: https://projecteuler.net/problem=500
To find the smallest number with 2^n divisors:
Building a table with columns:
n, n^2, n^4, n^8, n^16, ...
Build a generator to generate these numbers dynamically.
- List of primes from sieve.
- List of queues or sub-generators, each accessing the list of primes and an internal counter
Ask the generator to populate up to MAX:
- It will generate all primes up to MAX
- It will decide the order in which to serve these up
How many primes up do we go for each column?
- If the number we are considering is above p, then we want to include p in the queue of primes that will be served up.
- If the number we are considering is above p^2, then we want to include p^2 in the queue of primes that will be served up.
- etc...
Take the first element in the primes array, square it, and if we're above that, include it
