Expected Code Length

Problem

Given a probability distribution probs and matching integer codeword lengths, return the expected code length:

L = sum(p_i * l_i)

The two lists have the same length.

Hint

Weight each codeword length by the probability of the symbol it encodes.

case 1

in: [[0.5,0.25,0.25],[1,2,2]]

expected: 1.5

case 2

in: [[0.5,0.5],[1,1]]

expected: 1

case 3

in: [[0.25,0.25,0.25,0.25],[2,2,2,2]]

expected: 2

case 4

in: [[0.1,0.9],[4,1]]

expected: 1.3

Starter codePython

def expected_code_length(probs, lengths):
    # Your code here
    pass

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