Merge pull request #123 from theycallmemac/master

added timsort.py

sorts/timsort.py

@@ -0,0 +1,81 @@
+def binary_search(lst, item, start, end):
+    if start == end:
+        if lst[start] > item:
+            return start
+        else:
+            return start + 1
+    if start > end:
+        return start
+
+    mid = (start + end) // 2
+    if lst[mid] < item:
+        return binary_search(lst, item, mid + 1, end)
+    elif lst[mid] > item:
+        return binary_search(lst, item, start, mid - 1)
+    else:
+        return mid
+
+
+def insertion_sort(lst):
+    length = len(lst)
+
+    for index in range(1, length):
+        value = lst[index]
+        pos = binary_search(lst, value, 0, index - 1)
+        lst = lst[:pos] + [value] + lst[pos:index] + lst[index+1:]
+
+    return lst
+
+
+def merge(left, right):
+    if not left:
+        return right
+
+    if not right:
+        return left
+
+    if left[0] < right[0]:
+        return [left[0]] + merge(left[1:], right)
+
+    return [right[0]] + merge(left, right[1:])
+
+
+def timsort(lst):
+    runs, sorted_runs = [], []
+    length = len(lst)
+    new_run = [lst[0]]
+    sorted_array = []
+
+    for i in range(1, length):
+        if i == length - 1:
+            new_run.append(lst[i])
+            runs.append(new_run)
+            break
+
+        if lst[i] < lst[i - 1]:
+            if not new_run:
+                runs.append([lst[i - 1]])
+                new_run.append(lst[i])
+            else:
+                runs.append(new_run)
+                new_run = []
+        else:
+            new_run.append(lst[i])
+
+    for run in runs:
+        sorted_runs.append(insertion_sort(run))
+
+    for run in sorted_runs:
+        sorted_array = merge(sorted_array, run)
+
+    return sorted_array
+
+
+def main():
+
+    lst = [5,9,10,3,-4,5,178,92,46,-18,0,7]
+    sorted_lst = timsort(lst)
+    print(sorted_lst)
+
+if __name__ == '__main__':
+    main()