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https://github.com/TheAlgorithms/Python.git
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69 lines
1.9 KiB
Python
69 lines
1.9 KiB
Python
def binary_search(the_array, item, start, end):
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if start == end:
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if the_array[start] > item:
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return start
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else:
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return start + 1
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if start > end:
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return start
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mid = (start + end)/ 2
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if the_array[mid] < item:
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return binary_search(the_array, item, mid + 1, end)
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elif the_array[mid] > item:
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return binary_search(the_array, item, start, mid - 1)
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else:
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return mid
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"""
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Insertion sort that the heap sort uses if the array size is small or if
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the size of the "run" is small
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"""
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def insertion_sort(the_array):
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l = len(the_array)
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for index in range(1, l):
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value = the_array[index]
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pos = binary_search(the_array, value, 0, index - 1)
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the_array = the_array[:pos] + [value] + the_array[pos:index] + the_array[index+1:]
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return the_array
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def merge(left, right):
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"""Takes two sorted lists and returns a single sorted list by comparing the
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elements one at a time.
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[1, 2, 3, 4, 5, 6]
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"""
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if not left:
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return right
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if not right:
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return left
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if left[0] < right[0]:
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return [left[0]] + merge(left[1:], right)
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return [right[0]] + merge(left, right[1:])
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def timsort(the_array):
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runs, sorted_runs = [], []
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l = len(the_array)
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new_run = [the_array[0]]
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for i in range(1, l):
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if i == l-1:
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new_run.append(the_array[i])
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runs.append(new_run)
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break
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if the_array[i] < the_array[i-1]:
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if not new_run:
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runs.append([the_array[i-1]])
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new_run.append(the_array[i])
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else:
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runs.append(new_run)
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new_run = []
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else:
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new_run.append(the_array[i])
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for each in runs:
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sorted_runs.append(insertion_sort(each))
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sorted_array = []
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for run in sorted_runs:
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sorted_array = merge(sorted_array, run)
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print(sorted_array)
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