AllAlgorithms · abranhe · Oct 1, 2019 · Oct 1, 2019
diff --git a/sorting/counting_sort.py b/sorting/counting_sort.py
@@ -0,0 +1,35 @@
+#
+# Python implementation of counting sort.
+#
+#
+# The All ▲lgorithms Project
+#
+# https://allalgorithms.com/
+# https://github.com/allalgorithms/cpp
+#
+# Contributed by: Simon Faillace Mullen
+# Github: @macmullen
+#
+
+
+def counting_sort(arr):
+    # Create the counting sort array with length equal to the maximum number
+    # in the list.
+    count_array = [0] * (max(arr) + 1)
+    # Count the amount of repetitions for each number.
+    for number in arr:
+        count_array[number] += 1
+    # Append the amount of repetitions in order.
+    position = 0
+    for index, number in enumerate(count_array):
+        for amount in range(count_array[index]):
+            arr[position] = index
+            position += 1
+
+
+arr = [8, 5, 8, 4, 3, 3, 2, 1, 5, 5, 5, 9, 7, 7, 8, 1, 9, 3, 2]
+print("Unsorted array:")
+print(arr)
+counting_sort(arr)
+print("Sorted array:")
+print(arr)