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Challenges Fibonacci without consecutive digits

Output the Nth number in the list of Fibonacci numbers that have no consecutive digits. Input A non-negative integer (if you treat the Fibonacci numbers as zero-indexed) or a positive integer (...

4 answers  ·  posted 10mo ago by trichoplax‭  ·  last activity 3mo ago by Andrew Ray‭

#2: Post edited by user avatar trichoplax‭ · 2024-08-18T10:54:05Z (4 months ago)
Allow either zero-indexed or one-indexed Fibonacci numbers
  • Output the Nth number in the list of [Fibonacci numbers](https://en.wikipedia.org/wiki/Fibonacci_sequence) that have no consecutive digits.
  • ## Input
  • - A non-negative integer.
  • ## Output
  • - The Nth number in the list of Fibonacci numbers whose base 10 (decimal) representation has no adjacent digits that are consecutive.
  • - The Fibonacci numbers start with 0 and 1, then each subsequent Fibonacci number is the sum of the previous two Fibonacci numbers.
  • - The Fibonacci numbers are zero indexed:
  • - For input 0, the output is 0.
  • - For input 1, the output is 1.
  • - Two digits are consecutive if their absolute difference is 1.
  • - The consecutive digits can be in either ascending or descending order - either will lead to exclusion from the list.
  • ## Examples
  • ### Single digit Fibonacci numbers
  • - A single digit number has no adjacent digits, so all single digit Fibonacci numbers are included.
  • ### Two digit Fibonacci numbers
  • - 34 and 89 are excluded because their digits are consecutive.
  • - 21 is also excluded due to consecutive digits in descending order.
  • ### Non-adjacent consecutive digits
  • - 46368 contains the digits 4 and 3, which are consecutive digits. However, they are not adjacent (being separated by a 6) so 46368 is included.
  • ## Test cases
  • Test cases are in the format `input : output`.
  • ```text
  • 0 : 0
  • 1 : 1
  • 2 : 1
  • 3 : 2
  • 4 : 3
  • 5 : 5
  • 6 : 8
  • 7 : 13
  • 8 : 55
  • 9 : 144
  • 10 : 377
  • 11 : 1597
  • 12 : 2584
  • 13 : 4181
  • 14 : 17711
  • 15 : 46368
  • 16 : 75025
  • 17 : 196418
  • 18 : 514229
  • 19 : 14930352
  • 20 : 39088169
  • ```
  • ## Scoring
  • This is a [code golf challenge]. Your score is the number of bytes in your code. Lowest score for each language wins.
  • > Explanations are optional, but I'm more likely to upvote answers that have one.
  • [code golf challenge]: https://codegolf.codidact.com/categories/49/tags/4274 "The code-golf tag"
  • Output the Nth number in the list of [Fibonacci numbers](https://en.wikipedia.org/wiki/Fibonacci_sequence) that have no consecutive digits.
  • ## Input
  • - A non-negative integer (if you treat the Fibonacci numbers as zero-indexed) or a positive integer (if you treat the Fibonacci numbers as one-indexed).
  • ## Output
  • - The Nth number in the list of Fibonacci numbers whose base 10 (decimal) representation has no adjacent digits that are consecutive.
  • - The Fibonacci numbers start with 0 and 1, then each subsequent Fibonacci number is the sum of the previous two Fibonacci numbers.
  • - You may choose to treat the Fibonacci numbers as either zero-indexed or one-indexed. Either way, the Fibonacci numbers begin with zero:
  • - Zero-indexed: For input 0, the output is 0.
  • - One-indexed: For input 1, the output is 0.
  • - Two digits are consecutive if their absolute difference is 1.
  • - The consecutive digits can be in either ascending or descending order - either will lead to exclusion from the list.
  • ## Examples
  • ### Single digit Fibonacci numbers
  • - A single digit number has no adjacent digits, so all single digit Fibonacci numbers are included.
  • ### Two digit Fibonacci numbers
  • - 34 and 89 are excluded because their digits are consecutive.
  • - 21 is also excluded due to consecutive digits in descending order.
  • ### Non-adjacent consecutive digits
  • - 46368 contains the digits 4 and 3, which are consecutive digits. However, they are not adjacent (being separated by a 6) so 46368 is included.
  • ## Test cases
  • Test cases are in the format `input : output`.
  • ### Zero-indexed test cases
  • ```text
  • 0 : 0
  • 1 : 1
  • 2 : 1
  • 3 : 2
  • 4 : 3
  • 5 : 5
  • 6 : 8
  • 7 : 13
  • 8 : 55
  • 9 : 144
  • 10 : 377
  • 11 : 1597
  • 12 : 2584
  • 13 : 4181
  • 14 : 17711
  • 15 : 46368
  • 16 : 75025
  • 17 : 196418
  • 18 : 514229
  • 19 : 14930352
  • 20 : 39088169
  • ```
  • ### One-indexed test cases
  • ```text
  • 1 : 0
  • 2 : 1
  • 3 : 1
  • 4 : 2
  • 5 : 3
  • 6 : 5
  • 7 : 8
  • 8 : 13
  • 9 : 55
  • 10 : 144
  • 11 : 377
  • 12 : 1597
  • 13 : 2584
  • 14 : 4181
  • 15 : 17711
  • 16 : 46368
  • 17 : 75025
  • 18 : 196418
  • 19 : 514229
  • 20 : 14930352
  • 21 : 39088169
  • ```
  • ## Scoring
  • This is a [code golf challenge]. Your score is the number of bytes in your code. Lowest score for each language wins.
  • > Explanations are optional, but I'm more likely to upvote answers that have one.
  • [code golf challenge]: https://codegolf.codidact.com/categories/49/tags/4274 "The code-golf tag"
#1: Initial revision by user avatar trichoplax‭ · 2024-02-19T15:02:58Z (10 months ago)
Fibonacci without consecutive digits
Output the Nth number in the list of [Fibonacci numbers](https://en.wikipedia.org/wiki/Fibonacci_sequence) that have no consecutive digits.

## Input
- A non-negative integer.

## Output
- The Nth number in the list of Fibonacci numbers whose base 10 (decimal) representation has no adjacent digits that are consecutive.
- The Fibonacci numbers start with 0 and 1, then each subsequent Fibonacci number is the sum of the previous two Fibonacci numbers.
- The Fibonacci numbers are zero indexed:
  - For input 0, the output is 0.
  - For input 1, the output is 1.
- Two digits are consecutive if their absolute difference is 1.
- The consecutive digits can be in either ascending or descending order - either will lead to exclusion from the list.

## Examples
### Single digit Fibonacci numbers
- A single digit number has no adjacent digits, so all single digit Fibonacci numbers are included.

### Two digit Fibonacci numbers
- 34 and 89 are excluded because their digits are consecutive.
- 21 is also excluded due to consecutive digits in descending order.

### Non-adjacent consecutive digits
- 46368 contains the digits 4 and 3, which are consecutive digits. However, they are not adjacent (being separated by a 6) so 46368 is included.

## Test cases
Test cases are in the format `input : output`.

```text
0 : 0
1 : 1
2 : 1
3 : 2
4 : 3
5 : 5
6 : 8
7 : 13
8 : 55
9 : 144
10 : 377
11 : 1597
12 : 2584
13 : 4181
14 : 17711
15 : 46368
16 : 75025
17 : 196418
18 : 514229
19 : 14930352
20 : 39088169
```

## Scoring
This is a [code golf challenge]. Your score is the number of bytes in your code. Lowest score for each language wins.

> Explanations are optional, but I'm more likely to upvote answers that have one.


[code golf challenge]: https://codegolf.codidact.com/categories/49/tags/4274 "The code-golf tag"