Day 09

Task

1. Mix -nacci sequences using a given pattern p.
2. Return the first n elements of the mixed sequence.

Rules

1. The pattern p is given as a list of strings (or array of symbols in Ruby) using the pattern mapping below (e. g. ['fib', 'pad', 'pel'] means take the next fibonacci, then the next padovan, then the next pell number and so on).
2. When n is 0 or p is empty return an empty list.
3. If the length of p is more than n repeat the pattern.

Examples

            0  1  2  3  4  
----------+------------------
fibonacci:| 0, 1, 1, 2, 3 ...
padovan:  | 1, 0, 0, 1, 0 ...
pell:     | 0, 1, 2, 5, 12 ...

pattern = ['fib', 'pad', 'pel']
n = 6
#          ['fib',        'pad',      'pel',   'fib',        'pad',      'pel']
# result = [fibonacci(0), padovan(0), pell(0), fibonacci(1), padovan(1), pell(1)]
result = [0, 1, 0, 1, 0, 1]

pattern = ['fib', 'fib', 'pel']
n = 6
#          ['fib', 'fib', 'pel', 'fib', 'fib', 'pel']
# result = [fibonacci(0), fibonacci(1), pell(0), fibonacci(2), fibonacci(3), pell(1)]
result = [0, 1, 0, 1, 2, 1]

Sequences

• fibonacci : 0, 1, 1, 2, 3 ...
• padovan: 1, 0, 0, 1, 0 ...
• jacobsthal: 0, 1, 1, 3, 5 ...
• pell: 0, 1, 2, 5, 12 ...
• tribonacci: 0, 0, 1, 1, 2 ...
• tetranacci: 0, 0, 0, 1, 1 ...

Pattern mapping

• 'fib' -> fibonacci
• 'pad' -> padovan
• 'jac' -> jacobstahl
• 'pel' -> pell
• 'tri' -> tribonacci
• 'tet' -> tetranacci

Sample Tests:

[[[], 10], []],

  [[['fib'], 0], []],

  [[['fib'], 10], [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]],

  [[['pad'], 10], [1, 0, 0, 1, 0, 1, 1, 1, 2, 2]],

  [[['jac'], 10], [0, 1, 1, 3, 5, 11, 21, 43, 85, 171]],

  [[['pel'], 10], [0, 1, 2, 5, 12, 29, 70, 169, 408, 985]],

  [[['tri'], 10], [0, 0, 1, 1, 2, 4, 7, 13, 24, 44]],

  [[['tet'], 10], [0, 0, 0, 1, 1, 2, 4, 8, 15, 29]],

  [[['fib', 'tet'], 10], [0, 0, 1, 0, 1, 0, 2, 1, 3, 1]],

  [[['jac', 'jac', 'pel'], 10], [0, 1, 0, 1, 3, 1, 5, 11, 2, 21]]