Kata

Task

Given an array containing bits, can you find out the mysterious normalisation method and output the normalised array?

Input

array

• array containing bits
• a bit can have two possible values: 0 or 1
• 0 ≤ array length ≤ 100

Output

• return the normalised array
• different input arrays can have the same normalised array
• the first two elements of the input array decide the faith of the all bits in the normalised array
• normalisation is a mysterious process which you have to figure out

Code Golf Requirement

• the code length must not exceed 55 characters

Tests

• this is a puzzle, more test cases can be found in the sample tests
  • [0, 1] -> [1, 0]
  • [1, 0, 1] -> [0, 1, 0]
  • [0, 0, 1, 1, 0] -> [1, 1, 0, 1, 0]
  • [1, 0, 0, 1, 0, 0, 1, 0, 0] -> [0, 1, 0, 0, 0, 1, 0, 1, 0]
• random tests load:
  • 50 random tests with 0 ≤ array length ≤ 3
  • 50 random tests with 4 ≤ array length ≤ 7
  • 50 random tests with 8 ≤ array length ≤ 15
  • 50 random tests with 16 ≤ array length ≤ 49
  • 100 random tests with 50 ≤ array length ≤ 100

Hints (click to expand)

So you need some hints, eh? Ah well, here you go ..

• bits love to toggle
• patterns love to recur in very small prime sizes
• the first two elements of the input array each start a pattern; one has priority over the other