From ac25435d50cf455effeddf9bf0ef39eb09915a7e Mon Sep 17 00:00:00 2001
From: "lynn [they]" <lynncyrin@gmail.com>
Date: Sun, 23 Feb 2020 10:39:43 -0800
Subject: [PATCH] Rust selection sort (#65)

* expand clean, allow all keyword matching

* change keyword to any

* update CI

* update readme

* shorten

* update readme

* rust selection sort

* checkpoint insertion sort
---
 src/rust/Cargo.toml             |  4 ++
 src/rust/sort_selection_sort.rs | 75 +++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)
 create mode 100644 src/rust/sort_selection_sort.rs

diff --git a/src/rust/Cargo.toml b/src/rust/Cargo.toml
index 1a1a780..b4cc8a4 100644
--- a/src/rust/Cargo.toml
+++ b/src/rust/Cargo.toml
@@ -13,3 +13,7 @@ name = "sort_bubble_sort"
 [[bin]]
 path = "sort_insertion_sort.rs"
 name = "sort_insertion_sort"
+
+[[bin]]
+path = "sort_selection_sort.rs"
+name = "sort_selection_sort"
diff --git a/src/rust/sort_selection_sort.rs b/src/rust/sort_selection_sort.rs
new file mode 100644
index 0000000..a022830
--- /dev/null
+++ b/src/rust/sort_selection_sort.rs
@@ -0,0 +1,75 @@
+use std::env;
+use std::fs;
+use std::fs::File;
+use std::io::Write;
+
+///////////////////////
+// sort script start //
+///////////////////////
+
+// selection sort!
+//
+// docs: https://en.wikipedia.org/wiki/Selection_sort
+//
+// Selection sort looks through every element an input list, and finds the smallest element.
+// That element is then appended to the end of an output list. Which it reaches the end
+// of the input list, all of the output elements will be sorted.
+
+fn do_sorting(input_list: Vec<&str>) -> Vec<&str> {
+  return selection_sort(input_list);
+}
+
+fn selection_sort(input_list: Vec<&str>) -> Vec<&str> {
+  let mut sorted_elements: Vec<&str> = vec![];
+  let mut unsorted_elements: Vec<&str> = input_list;
+
+  for _ in 0..unsorted_elements.len() {
+    let smallest_index = find_smallest_index(&unsorted_elements);
+    let smallest_element = unsorted_elements[smallest_index];
+    sorted_elements.push(smallest_element);
+    unsorted_elements.remove(smallest_index);
+  }
+
+  return sorted_elements;
+}
+
+fn find_smallest_index(input_list: &Vec<&str>) -> usize {
+  let mut smallest_index: usize = 0;
+
+  for (index, element) in input_list.iter().enumerate() {
+    if element < &input_list[smallest_index] {
+      smallest_index = index;
+    }
+  }
+
+  return smallest_index;
+}
+
+/////////////////////
+// sort script end //
+/////////////////////
+
+// 👇🏽 copy pasted helpers
+
+fn main() -> Result<(), Box<dyn std::error::Error + 'static>> {
+  // setup
+  let input_file_path = env::var("INPUT_PATH").unwrap();
+  let output_file_path = env::var("OUTPUT_PATH").unwrap();
+
+  // get input data
+  let input_data_string = fs::read_to_string(input_file_path)?;
+  let input_data_vec = input_data_string.lines().collect();
+
+  // do sorting
+  let sorted_data = do_sorting(input_data_vec);
+
+  // write output data
+  // join on \n, and add an additional trailing \n
+  let output_data_string = sorted_data.join("\n") + "\n";
+  let output_data_bytes = output_data_string.as_bytes();
+  let mut output_file = File::create(output_file_path)?;
+  output_file.write_all(output_data_bytes)?;
+
+  // teardown
+  Ok(())
+}