* Added doctests to min_cost_string_conversion.py and removed :c specifier
* [pre-commit.ci] auto fixes from pre-commit.com hooks
for more information, see https://pre-commit.ci
* resolved line length issues based on ruff requirements
* modified in compliance with ruff for line length
* Update strings/min_cost_string_conversion.py
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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Tianyi Zheng <tianyizheng02@gmail.com>