Reworked notebook: Added more detail to constraints and test cases. Reworked unit test.

This commit is contained in:
Donne Martin 2015-06-27 06:34:09 -04:00
parent d3bd1fa290
commit 8c93b51fc6

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@ -13,21 +13,26 @@
"source": [
"## Problem: Sort a stack. You can use another stack as a buffer.\n",
"\n",
"* [Clarifying Questions](#Clarifying-Questions)\n",
"* [Constraints and Assumptions](#Constraints-and-Assumptions)\n",
"* [Test Cases](#Test-Cases)\n",
"* [Algorithm](#Algorithm)\n",
"* [Code](#Code)"
"* [Code](#Code)\n",
"* [Unit Test](#Unit-Test)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Clarifying Questions\n",
"## Constraints and Assumptions\n",
"\n",
"*Problem statements are often intentionally ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
"\n",
"* When sorted, should the largest element be at the top or bottom?\n",
" * Top\n",
"* Can you have duplicate values, saw two 5s?\n",
"* Can you have duplicate values like 5, 5?\n",
" * Yes\n",
"* Can we assume we already have a stack class that can be used for this problem?\n",
" * Yes"
]
},
@ -71,7 +76,7 @@
},
{
"cell_type": "code",
"execution_count": null,
"execution_count": 1,
"metadata": {
"collapsed": true
},
@ -82,7 +87,7 @@
},
{
"cell_type": "code",
"execution_count": null,
"execution_count": 2,
"metadata": {
"collapsed": false
},
@ -99,32 +104,68 @@
" return buff"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Unit Test\n",
"\n",
"*It is important to identify and run through general and edge cases from the [Test Cases](#Test-Cases) section by hand. You generally will not be asked to write a unit test like what is shown below.*"
]
},
{
"cell_type": "code",
"execution_count": null,
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [],
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Test: Empty stack\n",
"Test: One element stack\n",
"Test: Two or more element stack (general case)\n",
"Success: test_sort_stack\n"
]
}
],
"source": [
"from random import randint\n",
"from nose.tools import assert_equal\n",
"\n",
"def test_sort(num_items, stack=None):\n",
" if stack is None:\n",
"class Test(object):\n",
" def get_sorted_stack(self, numbers):\n",
" stack = MyStack()\n",
" for _ in xrange(0, num_items):\n",
" stack.push(randint(0, num_items))\n",
" sorted_stack = stack.sort()\n",
" for _ in xrange(0, num_items):\n",
" print(sorted_stack.pop())\n",
" return sorted_stack\n",
" for x in numbers:\n",
" stack.push(x)\n",
" sorted_stack = stack.sort()\n",
" return sorted_stack\n",
"\n",
"print('Empty stack')\n",
"test_sort(0)\n",
"print('One element stack')\n",
"test_sort(1)\n",
"print('Two or more element stack (general case)')\n",
"sorted_stack = test_sort(5)"
" def test_sort_stack(self):\n",
" print('Test: Empty stack')\n",
" sorted_stack = self.get_sorted_stack([])\n",
" assert_equal(sorted_stack.pop(), None)\n",
"\n",
" print('Test: One element stack')\n",
" sorted_stack = self.get_sorted_stack([1])\n",
" assert_equal(sorted_stack.pop(), 1)\n",
"\n",
" print('Test: Two or more element stack (general case)')\n",
" num_items = 10\n",
" numbers = [randint(0, 10) for x in xrange(num_items)]\n",
" sorted_stack = self.get_sorted_stack(numbers)\n",
" sorted_numbers = []\n",
" for _ in xrange(num_items):\n",
" sorted_numbers.append(sorted_stack.pop())\n",
" assert_equal(sorted_numbers, sorted(numbers, reverse=True))\n",
" \n",
" print('Success: test_sort_stack')\n",
"\n",
"if __name__ == '__main__':\n",
" test = Test()\n",
" test.test_sort_stack()"
]
}
],