freeCodeCamp/problem-70-totient-permutation.english.md at 209d41fcdd7ab7b0372ca4af123dd426790b4d32

Files

Daksh Goyal 209d41fcdd Fixes a Typo in Project Euler Problem 70 (#38782 )

* Fixed a Typo in Eulers Problem 70

Line 15 should say "Find the value of <var>n</var>, 1 < <var>n</var> < 10**7, for which φ(<var>n</var>) is a permutation of <var>n</var> and the ratio <var>n</var>/φ(<var>n</var>) produces a minimum." instead of Find the value of <var>n</var>, 1 < <var>n</var> < 107, for which φ(<var>n</var>) is a permutation of <var>n</var> and the ratio <var>n</var>/φ(<var>n</var>) produces a minimum.

* Updated the Markdown 

Fixes the markdown to display proper superscript rather than just using ** to denote a superscript

2020-05-11 07:35:16 -05:00

1.5 KiB

Raw Blame History

id, challengeType, title, forumTopicId

id	challengeType	title	forumTopicId
5900f3b21000cf542c50fec5	5	Problem 70: Totient permutation	302183

Description

Euler's Totient function, φ(n) [sometimes called the phi function], is used to determine the number of positive numbers less than or equal to n which are relatively prime to n. For example, as 1, 2, 4, 5, 7, and 8, are all less than nine and relatively prime to nine, φ(9)=6. The number 1 is considered to be relatively prime to every positive number, so φ(1)=1.

Interestingly, φ(87109)=79180, and it can be seen that 87109 is a permutation of 79180.

Find the value of n, 1 < n < 10⁷, for which φ(n) is a permutation of n and the ratio n/φ(n) produces a minimum.

Instructions

Tests

tests:
  - text: <code>totientPermutation()</code> should return a number.
    testString: assert(typeof totientPermutation() === 'number');
  - text: <code>totientPermutation()</code> should return 8319823.
    testString: assert.strictEqual(totientPermutation(), 8319823);

Challenge Seed

function totientPermutation() {
  // Good luck!
  return true;
}

totientPermutation();

Solution

// solution required

1.5 KiB Raw Blame History