chore(Python): add comb_sort (#244)

algorithms/Python/README.md

@@ -20,9 +20,10 @@
  
 ## Sorting
 1. [Bubble Sort](sorting/bubble_sort.py)
-2. [Insertion Sort](sorting/insertion_sort.py)
+2. [Comb Sort](sorting/comb_sort.py)
-3. [Quicksort](sorting/quicksort.py)
+3. [Insertion Sort](sorting/insertion_sort.py)
-4. [Selection Sort](sorting/selection_sort.py)
+4. [Quicksort](sorting/quicksort.py)
+5. [Selection Sort](sorting/selection_sort.py)
  
 ## Strings
 1. [Is Good Str](strings/is_good_str.py)

algorithms/Python/sorting/comb_sort.py

@@ -0,0 +1,34 @@
+'''
+Comb sort is a comparison based sorting algorithm and is an improved from of bubble sort. 
+
+Best case time complexity Θ(n log n)
+Worst case time complexity O(n^2)
+'''
+
+arr = [12, 3, 7, 22, -12, 100, 1]
+
+
+def combSort(arr):
+    """
+    >>> combSort(arr)
+    [-12, 1, 3, 7, 12, 22, 100]
+    """
+    gap = len(arr)
+    shrink = int(gap * 10 / 13)
+    sorted = False
+    while gap > 1 or sorted == False:
+        gap = int(gap / shrink)
+        if gap <= 1:
+            gap = 1
+            sorted = True
+        for i in range(len(arr)-gap):
+            if arr[i] > arr[i+gap]:
+                arr[i], arr[i+gap] = arr[i+gap], arr[i]
+                sorted = False
+    return arr
+
+
+combSort(arr)
+print("Sorted array is : ")
+for ele in arr:
+    print(ele)