MediumProbabilitypr-390

Random Walk Return After Even Steps

Problem

A simple symmetric random walk returns to the origin after 2k steps with probability C(2k, k) / 4^k.

Given k, return the return probability.

Hint

Half the steps must be up, half down.

case 1

in: [1]

expected: 0.5

case 2

in: [2]

expected: 0.375

case 3

in: [5]

expected: 0.24609375

Starter codePython

def random_walk_return_after_even_steps(k):
    # Your code here
    pass

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