These define three classifications of positive integers based on their proper divisors.
Let $P(n)$ be the sum of the proper divisors of n where proper divisors are all positive integers n other than n itself.
If P(n) < n
then n is classed as "deficient"
If P(n) === n
then n is classed as "perfect"
If P(n) > n
then n is classed as "abundant"
Example:
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Implement a function that calculates how many of the integers from 1 to 20,000 (inclusive) are in each of the three classes. Output the result as an array in the following format [deficient, perfect, abundant]
.
getDPA
is a function.
testString: assert(typeof getDPA === 'function', 'getDPA
is a function.');
- text: getDPA
should return an array.
testString: assert(Array.isArray(getDPA(100)), 'getDPA
should return an array.');
- text: getDPA
return value should have a length of 3.
testString: assert(getDPA(100).length === 3, 'getDPA
return value should have a length of 3.');
- text: getDPA(20000)
should equal [15043, 4, 4953]
testString: assert.deepEqual(getDPA(20000), solution, 'getDPA(20000)
should equal [15043, 4, 4953]');
```