RLE Compression Ratio

Problem

Run-length encoding stores every maximal run as a value plus a run count, so it needs 2 * runs integers for n input values. Return the ratio of encoded length to original length, which is 2 * runs / n. Return 0.0 for an empty list.

Hint

Long runs make the ratio small, while alternating values make it approach 2.

Test cases

case 1

in: [[1,1,1,1]]

expected: 0.5

case 2

in: [[1,2,3]]

expected: 2

case 3

in: [[1,1,2,2,2,1]]

expected: 1

case 4

in: [[]]

expected: 0

Starter codePython

def rle_compression_ratio(values):
    # Your code here
    pass

4 test cases · run your code against them in the editor