Rotate String Check

Problem

Return True if goal can be obtained by rotating s some number of positions to the left.

A rotation of s is always a substring of s concatenated with itself, so check membership of goal in s + s after confirming equal lengths. Empty strings rotate to each other.

Hint

s + s contains every rotation of s as a contiguous block.

Test cases

case 1

in: ["abcde","cdeab"]

expected: true

case 2

in: ["abcde","abced"]

expected: false

case 3

in: ["",""]

expected: true

case 4

in: ["a","a"]

expected: true

case 5

in: ["abc","cab"]

expected: true

Starter codePython

def rotate_string(s, goal):
    # Your code here
    pass

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