Create radix_sort.py

Author: abhisheks008

Sorting/Radix Sort/radix_sort.py

@@ -0,0 +1,101 @@
+# Problem Name: Radix Sort Algorithm
+# Problem Statement: Given an unsorted array of elements (here integers),
+#                    the task is to perform the Radix Sort algorithm to
+#                    sort the elements in the ascending order.
+
+# ------------------------------------------------------------------------------
+
+# Constraints: 
+# arr[] -> array of unsorted elements.
+# countingSort(arr, exp1) -> implementation of Counting Sort before Radix Sort.
+# radixSort(arr) -> implementation of Radix sort.
+
+# ------------------------------------------------------------------------------
+
+# Python program for implementation of Radix Sort
+# A function to do counting sort of arr[] according to
+# the digit represented by exp.
+ 
+def countingSort(arr, exp1):
+ 
+    n = len(arr)
+ 
+    # The output array elements that will have sorted arr
+    output = [0] * (n)
+ 
+    # initialize count array as 0
+    count = [0] * (10)
+ 
+    # Store count of occurrences in count[]
+    for i in range(0, n):
+        index = arr[i] // exp1
+        count[index % 10] += 1
+ 
+    # Change count[i] so that count[i] now contains actual
+    # position of this digit in output array
+    for i in range(1, 10):
+        count[i] += count[i - 1]
+ 
+    # Build the output array
+    i = n - 1
+    while i >= 0:
+        index = arr[i] // exp1
+        output[count[index % 10] - 1] = arr[i]
+        count[index % 10] -= 1
+        i -= 1
+ 
+    # Copying the output array to arr[],
+    # so that arr now contains sorted numbers
+    i = 0
+    for i in range(0, len(arr)):
+        arr[i] = output[i]
+ 
+# Method to do Radix Sort
+def radixSort(arr):
+ 
+    # Find the maximum number to know number of digits
+    max1 = max(arr)
+ 
+    # Do counting sort for every digit. Note that instead
+    # of passing digit number, exp is passed. exp is 10^i
+    # where i is current digit number
+    exp = 1
+    while max1 / exp >= 1:
+        countingSort(arr, exp)
+        exp *= 10
+ 
+ 
+# Driver code
+arr = [170, 45, 75, 90, 802, 24, 2, 66]
+
+print ("-- Implementation of Radix Sort Algorithm --")
+print ()
+print ("Array before implementing the Radix Sort...")
+print (" ".join(str(k) for k in arr))
+print ()
+print ("Radix Sort going on...")
+print ()
+print ("After implementing Radix Sort algorithm...")
+ 
+# Function Call
+radixSort(arr)
+print (" ".join(str(k) for k in arr)) 
+
+# ------------------------------------------------------------------------------
+
+# Output:
+# -- Implementation of Radix Sort Algorithm --
+
+# Array before implementing the Radix Sort...
+# 170 45 75 90 802 24 2 66
+
+# Radix Sort going on...
+
+# After implementing Radix Sort algorithm...
+# 2 24 45 66 75 90 170 802
+
+# ------------------------------------------------------------------------------
+
+# Code contributed by, Abhishek Sharma, 2022
+
+# ------------------------------------------------------------------------------