110 lines
2.6 KiB
Plaintext
110 lines
2.6 KiB
Plaintext
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Quick Sort\n",
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"© 2021, Joe James"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 84,
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"metadata": {},
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"outputs": [],
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"source": [
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"import random\n",
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"\n",
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"def quick_sort(A):\n",
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" quick(A, 0, len(A)-1)\n",
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"\n",
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"def quick(A, low, hi):\n",
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" if low < hi:\n",
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" p = partition(A, low, hi)\n",
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" quick(A, low, p-1)\n",
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" quick(A, p+1, hi)\n",
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"\n",
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"def get_pivot(A, low, hi):\n",
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" return random.randrange(low, hi+1)\n",
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" \n",
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"def partition(A, low, hi):\n",
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" pivotIndex = get_pivot(A, low, hi)\n",
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" pivotValue = A[pivotIndex]\n",
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" A[pivotIndex], A[low] = A[low], A[pivotIndex]\n",
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" border = low\n",
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"\n",
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" for i in range(low, hi+1):\n",
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" if A[i] < pivotValue:\n",
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" border += 1\n",
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" A[i], A[border] = A[border], A[i]\n",
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" A[low], A[border] = A[border], A[low]\n",
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"\n",
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" return (border)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Test Function\n",
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"Set a result flag. The j loop is used to perform 1000 test iterations. The next two lines create and shuffle list A of 100 integers. Then A is passed to our sorting function. The sorted result is compared to a sort using Python's sorted function. After 1000 iterations of the test, the result is printed."
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]
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},
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{
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"cell_type": "code",
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"execution_count": 85,
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"metadata": {},
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"outputs": [
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{
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"name": "stdout",
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"output_type": "stream",
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"text": [
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"Success\n"
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]
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}
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],
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"source": [
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"def test(func):\n",
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" result = 'Success'\n",
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" for j in range(1000):\n",
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" A = [k for k in range(100)]\n",
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" random.shuffle(A)\n",
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" func(A)\n",
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" if A != sorted(A):\n",
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" result += 'Failed' + str(j)\n",
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" print(result)\n",
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"test(quick_sort)"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": []
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 3",
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"language": "python",
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"name": "python3"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 3
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython3",
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"version": "3.7.0"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 2
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}
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