Is it an Arithmetic Sequence or not? [closed]

Question

Challenge

In this challenge, the input will be an ordered set of numbers and the program should be able to tell if the set of numbers is an Arithmetic Sequence.

Input

• The input will be a list separated by ,(comma) or , (comma+space). The minimum length of the list should be 3 elements.

Output

• The Output can be a Boolean (True or False), or a number (1 for True, 0 for False).

Test cases

In: 1, 3, 5
Out: True

In: 1,4, 7
Out: 1

In: 5, 9,10
Out: 0

In: 5,3,1
Out: False

Rules

• This is code-golf, so the shortest code by bytes wins.
• The input will be finite

Best of Luck

Answer 1

MathGolf, 5 bytes

ê│▀£┴

Input ,-delimited; outputs 1/0 for truthy/falsey respectively.

Try it online. (MathGolf is able to execute multiple test cases at once for each line of STDIN input, but feel free to only use a single input if you'd like.)

Explanation:

ê      # Read the comma-delimited input-string as integer-list
 │     # Get the forward differences of each overlapping pair in this list
  ▀    # Uniquify these differences
   £   # Pop and push the length to get the amount of unique differences
    ┴  # Check that this length is equal to 1 (1 if 1; 0 if >= 2)
       # (after which the entire stack joined together is output implicitly as result)

Answer 2

Retina 0.8.2, 47 bytes

\d+
$*
A`(1+),(?!\1)
(?<=(1+),)\1

^1*(,1*)\1*$

Try it online! Only works on nondescending sequences of at least two integers. Explanation:

\d+
$*

Convert to unary.

A`(1+),(?!\1)

Check that the sequence is ascending.

(?<=(1+),)\1

Compute the differences after the first value.

^1*(,1*)\1*$

Check that all of the differences are equal.

Answer 3

APL (Dyalog Unicode), 8 bytes (SBCS)

1=≢∪2-/⎕

Try it online!

1= Is 1 equal to

≢ the count of

∪ unique

2-/ pairwise differences

⎕ in the evaluated input?

The ⎕ prompts for input and executes it. Luckily, , is APL's concatenation functions, so the required input format evaluates to a list. Spaces are ignored.

Answer 4

05AB1E, 5 bytes

',¡¥Ë

Input ,-delimited; outputs 1/0 for truthy/falsey respectively.

Try it online or verify a few more test cases.

Explanation:

',¡   '# Split the (implicit) input-string on ","
   ¥   # Get the deltas (forward differences) of each overlapping pair in this list
    Ë  # Check if all differences are equal (1 if truthy; 0 if falsey)
       # (after which this result is output implicitly)

Of course, this would have been 2 bytes with default I/O rules by taking a list input: ¥Ë.