Tests need to be rewritten/randomized in Project Euler: Problem 69: Totient maximum

Describe your problem and how to reproduce it: I can just pass the challenge by typing

function totientMaximum() {
  // Good luck!
  return 510510;
}

Add a Link to the page with the problem: https://www.freecodecamp.org/learn/coding-interview-prep/project-euler/problem-69-totient-maximum

[thecodingaviator]

Thanks for reporting this @thecodingaviator. This is definitely something we want to improve over time.

I do agree that anyone who cheats is just cheating themselves, and a lot of the solutions are freely available online. Still, we want to avoid letting people return a single number and passing a challenge if possible.

One thing we’ve done is adapt the functions to take arguments, adjust the description, and add more tests. This one would be pretty easy to adapt because there’s a table with the answers in the description.

We could change the last sentence of the description to “Find the value of n ≤ limit for which n/φ(n) is a maximum.” Then we could add or adjust the tests so we’re checking for totientMaximum(10) and totientMaximum(1000000), which should return 6 and 510510, respectively.

Also we could add a solution like

function totientMaximum(limit) {
  let result = 1;
  const primes = [];
  let i = 0;

  const isPrime = num => {
    for (let i = 2; i <= Math.sqrt(num); i++) {
      if (num % i === 0) return false;
    }
    return num !== 0 && num !== 1;
  }
  
  for (let i = 2; i < 200; i++) {
    if (isPrime(i)) primes.push(i);
  }

  while(result * primes[i] < limit) {
    result *= primes[i];
    i++;
  }
  
  return result;
}

But that’s almost directly from this blog, so if there’s a more concise original solution, we should go with that.

What do you think @thecodingaviator and @Sky020?

Sounds awesome!

[moT01]

I think we are safe to close this in favor of the issue linked above. Thanks for all the input on this everyone. If anyone thinks I am wrong in closing this, feel free to leave a comment and we can reopen it. Thanks and happy coding 🎉