Update hanoi challenge (#121)

Update constraints and test cases.  Move implementation to a class.  Update tests.
This commit is contained in:
Donne Martin 2016-11-19 09:01:44 -05:00 committed by GitHub
parent 14de5e4233
commit 430cca2a01
3 changed files with 70 additions and 52 deletions

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@ -35,6 +35,10 @@
"## Constraints\n",
"\n",
"* Can we assume we already have a stack class that can be used for this problem?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
" * No\n",
"* Can we assume this fits memory?\n",
" * Yes"
]
},
@ -44,8 +48,8 @@
"source": [
"## Test Cases\n",
"\n",
"* None tower(s)\n",
"* 0 disks\n",
"* None tower(s) -> Exception\n",
"* 0 disks -> None\n",
"* 1 disk\n",
"* 2 or more disks"
]
@ -86,9 +90,11 @@
},
"outputs": [],
"source": [
"def hanoi(num_disks, src, dest, buff):\n",
" # TODO: Implement me\n",
" pass"
"class Hanoi(object):\n",
"\n",
" def move_disks(self, num_disks, src, dest, buff):\n",
" # TODO: Implement me\n",
" pass"
]
},
{
@ -111,35 +117,36 @@
"outputs": [],
"source": [
"# %load test_hanoi.py\n",
"from nose.tools import assert_equal\n",
"from nose.tools import assert_equal, assert_raises\n",
"\n",
"\n",
"class TestHanoi(object):\n",
"\n",
" def test_hanoi(self):\n",
" hanoi = Hanoi()\n",
" num_disks = 3\n",
" src = Stack()\n",
" buff = Stack()\n",
" dest = Stack()\n",
"\n",
" print('Test: None towers')\n",
" hanoi(num_disks, None, None, None)\n",
" assert_raises(TypeError, hanoi.move_disks, num_disks, None, None, None)\n",
"\n",
" print('Test: 0 disks')\n",
" hanoi(num_disks, src, dest, buff)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" assert_equal(dest.pop(), None)\n",
"\n",
" print('Test: 1 disk')\n",
" src.push(5)\n",
" hanoi(num_disks, src, dest, buff)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" assert_equal(dest.pop(), 5)\n",
"\n",
" print('Test: 2 or more disks')\n",
" for i in range(num_disks, -1, -1):\n",
" src.push(i)\n",
" hanoi(num_disks, src, dest, buff)\n",
" for i in range(0, num_disks):\n",
" assert_equal(dest.pop(), i)\n",
" for disk_index in range(num_disks, -1, -1):\n",
" src.push(disk_index)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" for disk_index in range(0, num_disks):\n",
" assert_equal(dest.pop(), disk_index)\n",
"\n",
" print('Success: test_hanoi')\n",
"\n",
@ -165,21 +172,21 @@
],
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"display_name": "Python 3",
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@ -34,6 +34,10 @@
"## Constraints\n",
"\n",
"* Can we assume we already have a stack class that can be used for this problem?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
" * No\n",
"* Can we assume this fits memory?\n",
" * Yes"
]
},
@ -43,8 +47,8 @@
"source": [
"## Test Cases\n",
"\n",
"* None tower(s)\n",
"* 0 disks\n",
"* None tower(s) -> Exception\n",
"* 0 disks -> None\n",
"* 1 disk\n",
"* 2 or more disks"
]
@ -93,14 +97,19 @@
},
"outputs": [],
"source": [
"def hanoi(num_disks, src, dest, buff):\n",
" if src is None or dest is None or buff is None:\n",
" return\n",
" if num_disks > 0:\n",
" hanoi(num_disks-1, src, buff, dest)\n",
" data = src.pop()\n",
" dest.push(data)\n",
" hanoi(num_disks-1, buff, dest, src)"
"class Hanoi(object):\n",
"\n",
" def move_disks(self, num_disks, src, dest, buff):\n",
" if src is None or dest is None or buff is None:\n",
" raise TypeError('Cannot have a None input')\n",
" self._move_disks(num_disks, src, dest, buff)\n",
"\n",
" def _move_disks(self, num_disks, src, dest, buff):\n",
" if num_disks == 0:\n",
" return\n",
" self.move_disks(num_disks-1, src, buff, dest)\n",
" dest.push(src.pop())\n",
" self.move_disks(num_disks-1, buff, dest, src)"
]
},
{
@ -128,35 +137,36 @@
],
"source": [
"%%writefile test_hanoi.py\n",
"from nose.tools import assert_equal\n",
"from nose.tools import assert_equal, assert_raises\n",
"\n",
"\n",
"class TestHanoi(object):\n",
"\n",
" def test_hanoi(self):\n",
" hanoi = Hanoi()\n",
" num_disks = 3\n",
" src = Stack()\n",
" buff = Stack()\n",
" dest = Stack()\n",
"\n",
" print('Test: None towers')\n",
" hanoi(num_disks, None, None, None)\n",
" assert_raises(TypeError, hanoi.move_disks, num_disks, None, None, None)\n",
"\n",
" print('Test: 0 disks')\n",
" hanoi(num_disks, src, dest, buff)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" assert_equal(dest.pop(), None)\n",
"\n",
" print('Test: 1 disk')\n",
" src.push(5)\n",
" hanoi(num_disks, src, dest, buff)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" assert_equal(dest.pop(), 5)\n",
"\n",
" print('Test: 2 or more disks')\n",
" for i in range(num_disks, -1, -1):\n",
" src.push(i)\n",
" hanoi(num_disks, src, dest, buff)\n",
" for i in range(0, num_disks):\n",
" assert_equal(dest.pop(), i)\n",
" for disk_index in range(num_disks, -1, -1):\n",
" src.push(disk_index)\n",
" hanoi.move_disks(num_disks, src, dest, buff)\n",
" for disk_index in range(0, num_disks):\n",
" assert_equal(dest.pop(), disk_index)\n",
"\n",
" print('Success: test_hanoi')\n",
"\n",
@ -196,21 +206,21 @@
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"nbformat": 4,

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@ -1,32 +1,33 @@
from nose.tools import assert_equal
from nose.tools import assert_equal, assert_raises
class TestHanoi(object):
def test_hanoi(self):
hanoi = Hanoi()
num_disks = 3
src = Stack()
buff = Stack()
dest = Stack()
print('Test: None towers')
hanoi(num_disks, None, None, None)
assert_raises(TypeError, hanoi.move_disks, num_disks, None, None, None)
print('Test: 0 disks')
hanoi(num_disks, src, dest, buff)
hanoi.move_disks(num_disks, src, dest, buff)
assert_equal(dest.pop(), None)
print('Test: 1 disk')
src.push(5)
hanoi(num_disks, src, dest, buff)
hanoi.move_disks(num_disks, src, dest, buff)
assert_equal(dest.pop(), 5)
print('Test: 2 or more disks')
for i in range(num_disks, -1, -1):
src.push(i)
hanoi(num_disks, src, dest, buff)
for i in range(0, num_disks):
assert_equal(dest.pop(), i)
for disk_index in range(num_disks, -1, -1):
src.push(disk_index)
hanoi.move_disks(num_disks, src, dest, buff)
for disk_index in range(0, num_disks):
assert_equal(dest.pop(), disk_index)
print('Success: test_hanoi')