From 380d901739c43b8c93d23f628fa6b247db14b64c Mon Sep 17 00:00:00 2001
From: alastairruhm <alastairruhm@gmail.com>
Date: Wed, 11 Apr 2018 16:01:31 +0800
Subject: [PATCH] quick sort

---
 algorithm/sorting/quick-sort/quick_sort.go    | 26 +++++++++++++++++++
 .../sorting/quick-sort/quick_sort_test.go     | 26 +++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 algorithm/sorting/quick-sort/quick_sort.go
 create mode 100644 algorithm/sorting/quick-sort/quick_sort_test.go

diff --git a/algorithm/sorting/quick-sort/quick_sort.go b/algorithm/sorting/quick-sort/quick_sort.go
new file mode 100644
index 0000000..e1a3279
--- /dev/null
+++ b/algorithm/sorting/quick-sort/quick_sort.go
@@ -0,0 +1,26 @@
+package quicksort
+
+// QuickSort ...
+func QuickSort(array []int) []int {
+	var sorted []int
+	if len(array) < 2 { // array is sorted if the length is 0 or 1,
+		sorted = array
+		// return array
+	} else {
+		pivot := array[0] // pivot value use to compare
+		var less []int
+		var greater []int
+		for _, e := range array[1:] {
+			if e <= pivot {
+				less = append(less, e)
+			} else {
+				greater = append(greater, e)
+			}
+		}
+		sorted = append(sorted, QuickSort(less)...)
+		sorted = append(sorted, pivot)
+		sorted = append(sorted, QuickSort(greater)...)
+		// return sorted
+	}
+	return sorted
+}
diff --git a/algorithm/sorting/quick-sort/quick_sort_test.go b/algorithm/sorting/quick-sort/quick_sort_test.go
new file mode 100644
index 0000000..40e486d
--- /dev/null
+++ b/algorithm/sorting/quick-sort/quick_sort_test.go
@@ -0,0 +1,26 @@
+package quicksort
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestQuickSort(t *testing.T) {
+	var cases = []struct {
+		input    []int
+		expected []int
+	}{
+		{[]int{5, 2, 1, 4, 3}, []int{1, 2, 3, 4, 5}},
+		{[]int{1, 5, 2, 4, 3}, []int{1, 2, 3, 4, 5}},
+	}
+	// Only pass t into top-level Convey calls
+	Convey("Quick Sort", t, func() {
+		Convey("ok", func() {
+			for _, c := range cases {
+				o := QuickSort(c.input)
+				So(o, ShouldResemble, c.expected)
+			}
+		})
+	})
+}