Minimum Swaps to Alternate a Binary String

Create a function that returns the minimum number of swaps it takes to transform a binary string into a string of alternating 0s and 1s. A swap is switching from a 0 to a 1 or vice versa.

Examples

min_swaps("010010111") ➞ 4

# Two possible conversions:
#   1. "101010101" (4 swaps)
#   2. "010101010" (5 swaps)

min_swaps("10101010") ➞ 0

min_swaps("10010") ➞ 2

Notes

N/A