quick sort added

.gitignore

@@ -27,4 +27,5 @@ sorting/bubble_sort
 sorting/selection_sort
 sorting/merge_sort
 sorting/cocktail_sort
-sorting/gnome_sort
+sorting/gnome_sort
+sorting/quick_sort

README.md

@@ -22,6 +22,7 @@ alghoritms
   * merge sort
   * cocktail sort
   * gnome sort
+  * quick sort
 
 contribution
 ------------

sorting/quick_sort.go

@@ -0,0 +1,49 @@
+package main
+
+/*
+ * Quick sort - https://en.wikipedia.org/wiki/Quicksort
+ */
+
+import "fmt"
+import "math/rand"
+
+import "github.com/0xAX/go-algorithms"
+
+func quick_sort(arr []int) []int {
+
+    if len(arr) <= 1 {
+        return arr
+    }
+
+    median := arr[rand.Intn(len(arr))]
+
+    low_part := make([]int, 0, len(arr))
+    high_part := make([]int, 0, len(arr))
+    middle_part := make([]int, 0, len(arr))
+
+    for _, item := range arr {
+        switch {
+        case item < median:
+            low_part = append(low_part, item)
+        case item == median:
+            middle_part = append(middle_part, item)
+        case item > median:
+            high_part = append(high_part, item)
+        }
+    }
+
+    low_part = quick_sort(low_part)
+    high_part = quick_sort(high_part)
+
+    low_part = append(low_part, middle_part...)
+    low_part = append(low_part, high_part...)
+
+    return low_part
+}
+
+func main() {
+    arr := utils.RandArray(10)
+    fmt.Println("Initial array is:", arr)
+    fmt.Println("")
+    fmt.Println("Sorted array is: ", quick_sort(arr))
+}