Arithmetic Coding CDF

Problem

Return the cumulative distribution boundaries used by an arithmetic coder: a list starting with 0.0 followed by the running cumulative sums of probs, so the result has len(probs) + 1 entries.

Hint

Symbol i occupies the interval [cdf[i], cdf[i + 1]).

Test cases

case 1

in: [[0.5,0.5]]

expected: [0,0.5,1]

case 2

in: [[0.25,0.25,0.25,0.25]]

expected: [0,0.25,0.5,0.75,1]

case 3

in: [[0.1,0.2,0.7]]

expected: [0,0.1,0.30000000000000004,1]

case 4

in: [[1]]

expected: [0,1]

Starter codePython

def arithmetic_cdf(probs):
    # Your code here
    pass

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