25 lines
855 B
Markdown
25 lines
855 B
Markdown
Insertion Sort
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==============
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Wikipedia on [insertion sort](http://en.wikipedia.org/wiki/Insertion_sort).
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#### Algorithm
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Insertion sort is a common sorting algorithm that, while still its worst case is still O(n**2), it is much more efficient than Bubble sort on average.
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According to wikipedia, when people manually sort something, like a deck of cards for example, most use a method similar to insertion sort.
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The algorithm is simple - here it is in pseudocode.
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```
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from i = 1 to length of array:
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j = i
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while j > 0 and array[j-1] > array[j]:
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swap array[j] and array[j-1]
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j = j - 1
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```
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#### Implementation
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Write a function `insertion_sort()` that takes an unsorted `list` and returns a sorted `list`, using the insertion sort algorithm.
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