Adding counting sort

Author: bhavnavarshney

Go/sorting/countingsort.go

@@ -0,0 +1,30 @@
+package sorting
+
+// Note: The array  can be sorted by using this algorithm only if the maximum value in array  is less than the
+// maximum size of the array . Usually, it is possible to allocate memory up to the order of a million .
+// If the maximum value of  exceeds the maximum memory- allocation size, it is recommended that you do not use this algorithm.
+// Use either the quick sort or merge sort algorithm.
+func countingSort(arr []int) {
+	max := len(arr)
+
+	for i := 0; i < len(arr); i++ {
+		if arr[i] > max {
+			max = arr[i]
+		}
+	}
+
+	aux := make([]int, max+1)
+
+	for i := 0; i < len(arr); i++ {
+		aux[arr[i]]++
+	}
+
+	k := 0
+	for i := 0; i < len(aux); i++ {
+		for aux[i] != 0 {
+			arr[k] = i
+			aux[i]--
+			k++
+		}
+	}
+}