Add sort utils fn and apply them to 3-way quick sort first. #620

	name: build

	on: pull_request

	jobs:
	fmt:
	name: cargo fmt
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: cargo fmt
	run: cargo fmt --all -- --check

	clippy:
	name: cargo clippy
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: cargo clippy
	run: cargo clippy --all --all-targets -- -D warnings

	test:
	name: cargo test
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: cargo test
	run: cargo test

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