From b607608b855b3fd31c36ca5ef4ad367d90a22770 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Christian=20Gr=C3=BCnhage?=
 <jan.christian@gruenhage.xyz>
Date: Sun, 27 Aug 2017 18:52:51 +0200
Subject: [PATCH] feat: add quicksort

---
 src/algorithms/mod.rs       |  1 +
 src/algorithms/quicksort.rs | 59 +++++++++++++++++++++++++++++++++++++
 src/main.rs                 |  4 +--
 3 files changed, 62 insertions(+), 2 deletions(-)
 create mode 100644 src/algorithms/quicksort.rs

diff --git a/src/algorithms/mod.rs b/src/algorithms/mod.rs
index ab5e21e..9d48bae 100644
--- a/src/algorithms/mod.rs
+++ b/src/algorithms/mod.rs
@@ -6,3 +6,4 @@ pub trait Algorithm {
 pub mod bubblesort;
 pub mod mergesort;
 pub mod insertionsort;
+pub mod quicksort;
diff --git a/src/algorithms/quicksort.rs b/src/algorithms/quicksort.rs
new file mode 100644
index 0000000..71c9a75
--- /dev/null
+++ b/src/algorithms/quicksort.rs
@@ -0,0 +1,59 @@
+use algorithms::Algorithm;
+
+pub struct Quicksort;
+
+impl Algorithm for Quicksort {
+    fn sort(mut vector: Vec<i32>) -> Result<Vec<i32>, &'static str> {
+        let pivot = match vector.pop() {
+            Some(v) => v,
+            None => return Ok(Vec::new()),
+        };
+        let mut pivots: Vec<i32> = Vec::new();
+        pivots.push(pivot);
+
+        let mut smaller: Vec<i32> = Vec::new();
+        let mut larger: Vec<i32> = Vec::new();
+
+        while vector.len() != 0 {
+            let element = match vector.pop() {
+                Some(v) => v,
+                None => {
+                    return Err(
+                        "Vector had a length not equal to 0, but still had no more element in it. This point should not be reachable.",
+                    )
+                }
+            };
+            if element < pivot {
+                smaller.push(element);
+            } else if element > pivot {
+                larger.push(element);
+            } else {
+                pivots.push(element);
+            }
+        }
+
+        let mut result: Vec<i32> = Vec::new();
+
+        for v in match Quicksort::sort(smaller) {
+            Ok(v) => v,
+            Err(e) => return Err(e),
+        }
+        {
+            result.push(v);
+        }
+
+        for v in pivots {
+            result.push(v);
+        }
+
+        for v in match Quicksort::sort(larger) {
+            Ok(v) => v,
+            Err(e) => return Err(e),
+        }
+        {
+            result.push(v);
+        }
+
+        return Ok(result);
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 5c63f76..9568228 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,11 +1,11 @@
 mod algorithms;
 
-use algorithms::insertionsort::Insertionsort;
+use algorithms::quicksort::Quicksort;
 use algorithms::Algorithm;
 
 fn main() {
     let unsorted: Vec<i32> = vec![2498, 29687, 24, 5, 94545, 8, 51, 152, 48, 871, 5];
-    let sorted = match Insertionsort::sort(unsorted) {
+    let sorted = match Quicksort::sort(unsorted) {
         Ok(v) => v,
         Err(e) => {
             println!("Something went wrong! {}", e);