Adding quicksort

Author: bhavnavarshney

Go/sorting/quicksort.go

@@ -0,0 +1,27 @@
+package sorting
+
+func partition(arr []int, start, end int) int {
+	pivotIndex := start
+	pivot := arr[start]
+
+	smaller := start + 1 // All elements less than pivot
+	larger := start + 1  // All elements greater than pivot
+
+	for larger = start + 1; larger <= end; larger++ {
+		if arr[larger] < pivot {
+			arr[smaller], arr[larger] = arr[larger], arr[smaller]
+			smaller++
+		}
+	}
+
+	// put pivot to it's right place
+	arr[pivotIndex], arr[smaller-1] = arr[smaller-1], arr[pivotIndex]
+	return smaller - 1 // Return the current pivot index!
+}
+func quickSort(arr []int, start, end int) {
+	if start < end {
+		pivotIndex := partition(arr, start, end)
+		quickSort(arr, start, pivotIndex)
+		quickSort(arr, pivotIndex+1, end)
+	}
+}