From 00f74245fb5bc3bd835aaa777de48b9dacc5dc33 Mon Sep 17 00:00:00 2001
From: Prathima Kadari <kadariprathima4@gmail.com>
Date: Sun, 30 May 2021 03:05:53 +0530
Subject: [PATCH] chore(Python): added radix sort program (#328)

Co-authored-by: Arsenic <54987647+Arsenic-ATG@users.noreply.github.com>
---
 algorithms/Python/README.md             |  1 +
 algorithms/Python/sorting/radix_sort.py | 47 +++++++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 algorithms/Python/sorting/radix_sort.py

diff --git a/algorithms/Python/README.md b/algorithms/Python/README.md
index a2d4dd27..d1caa623 100644
--- a/algorithms/Python/README.md
+++ b/algorithms/Python/README.md
@@ -29,6 +29,7 @@
 4. [Quicksort](sorting/quicksort.py)
 5. [Selection Sort](sorting/selection_sort.py)
 6. [Heap Sort](sorting/heap-sort.py)
+7. [Radix Sort](sorting/radix-sort.py)
  
 ## Strings
 1. [Is Good Str](strings/is_good_str.py)
diff --git a/algorithms/Python/sorting/radix_sort.py b/algorithms/Python/sorting/radix_sort.py
new file mode 100644
index 00000000..4bfc66cf
--- /dev/null
+++ b/algorithms/Python/sorting/radix_sort.py
@@ -0,0 +1,47 @@
+"""
+Radix Sort
+Time Complexity: O(nk + n). 
+n is the size of input list and k is the digit length of the number.
+"""
+
+def radix_sort(arr, simulation=False):
+    position = 1
+    max_number = max(arr)
+
+    iteration = 0
+    if simulation:
+        print("iteration", iteration, ":", *arr)
+
+    while position <= max_number:
+        queue_list = [list() for _ in range(10)]
+
+        for num in arr:
+            digit_number = num // position % 10
+            queue_list[digit_number].append(num)
+
+        index = 0
+        for numbers in queue_list:
+            for num in numbers:
+                arr[index] = num
+                index += 1
+
+        if simulation:
+            iteration = iteration + 1
+            print("iteration", iteration, ":", *arr)
+
+        position *= 10
+    return arr
+
+arr = [142, 34, 6, 17, 113, 2, 261, 72]
+
+if __name__ == "__main__":
+    print("Sorted Array:", radix_sort(arr))
+    
+# Runtime Test Cases:-
+# Test case 1.
+# Enter the list of numbers: 12 7 56 42
+# Sorted list: [7 12 42 56]
+# Test case 2.
+# Enter the list of numbers: 142 34 6 17 113 2 261 72 
+# Sorted list: [2 6 17 34 72 113 142 261]
+# For radix sort, Best = Worst = Average Time Complexity is O(nk+n).