def is_matched_html(raw):
""" Returns True if all HTML tags are properly matched, False otherwise """
S = ArrayStack()
j = raw.find('<') # find first < character if any
while j != -1:
k = raw.find(">",j+1) # find next > character if any
if k==-1:
return False # invalid tag
tag = raw[j+1:k] # dtrip away <>
if not tag.startswith('/'):
S.push(tag)
else:
if S.is_empty():
return False
if tag[1:] != S.pop():
return False
j = raw.find("<",k+1)
return S.is_empty()
class StackQueue:
def __init__(self):
self.stack1 = ArrayStack()
self.stack2 = ArrayStack()
self.count = 0
def enqueue(self, item):
self.stack1.push(item)
self.count += 1
def dequeue(self):
if self.is_empty():
raise ValueError("Empty Queue Error")
self.moveStack1ToStack2()
return self.stack2.pop()
def peek(self):
if self.is_empty():
raise ValueError("Empty Queue Error")
self.moveStack1ToStack2()
return self.stack2.peek()
def moveStack1ToStack2(self):
if self.stack2.is_empty():
while not self.stack1.is_empty():
self.stack2.push(self.stack1.pop())
def is_empty(self):
return self.stack1.is_empty() and self.stack2.is_empty()
def test_is_empty(self):
# empty stack
stack = ArrayStack()
self.assertTrue(stack.is_empty())
# non-empty stack
stack.push('a')
self.assertFalse(stack.is_empty())
def is_matched(expr):
lefty = '({['
righty = ')}]'
S = ArrayStack()
for c in expr:
if c in lefty:
S.push(c)
elif c in righty:
if S.is_empty():
return False
if righty.index(c) != lefty.index(S.pop()):
return False
return S.is_empty()
def is_matched(expr):
lefty = '({['
righty = ')}]'
S = ArrayStack()
for c in expr:
if c in lefty:
S.push(c)
elif c in righty:
if S.is_empty():
return False
if righty.index(c) != lefty.index(S.pop()):
return False
return S.is_empty()
def is_matched(expr):
""" Return True if all delimiters are properly match;False otherwise. """
lefty = '({['
righty = ')}]'
S = ArrayStack()
for c in expr:
if c in lefty:
S.push(c)
elif c in righty:
if S.is_empty():
return False
if righty.index(c) != lefty.index(S.pop()):
return False
return S.is_empty()
def balanced(expr):
''' checks if all the delimiters in an expression, expr, are balanced '''
lefts = '({[' # opening delimiters
rights = ')}]' # respective closing delimiters
stack = Stack()
for d in expr:
if d in lefts:
stack.push(d) # first left delimiter, save for later check
elif d in rights:
if stack.is_empty(): # closing delimiter with no matching opening delimiter
return False
if rights.index(d) != lefts.index(stack.pop()): #compare match
return False
return stack.is_empty() # check if all symbols were matched
def is_matched(expr):
""" Return True if all the delimeter are properly matched """
lefty = "({["
righty = ")}]"
S = ArrayStack()
for c in expr:
if c in lefty:
S.push(c)
elif c in righty:
if S.is_empty():
return False
if righty.index(c) != lefty.index(S.pop()):
return False
return S.is_empty()
class TestArrayStack(unittest.TestCase):
def setUp(self):
self.st = ArrayStack()
def tearDown(self):
del self.st
# default feature test - push, pop, peek
def test_01(self):
self.st.push(1)
self.st.push(2)
self.st.push(3)
self.assertEqual(self.st.peek(), 3)
self.assertEqual(self.st.pop(), 3)
self.assertEqual(self.st.peek(), 2)
self.assertEqual(self.st.pop(), 2)
self.assertEqual(self.st.peek(), 1)
self.assertEqual(self.st.pop(), 1)
# raise error when pop with empty stack
def test_02(self):
with self.assertRaises(IndexError) as cm:
self.st.pop()
self.assertEqual("stack is empty", str(cm.exception))
# test check empty
def test_03(self):
self.assertTrue(self.st.is_empty())
# test expand
def test_04(self):
self.assertEqual(len(self.st._array), 10)
for i in range(11):
self.st.push(i)
self.assertEqual(len(self.st._array), 20)
def is_matched_html(raw):
""" Return True if all HTML tags are properly match; False otherwise. """
S = ArrayStack()
# find():返回子字符串 sub 在 s[start:end] 切片内被找到的最小索引。 可选参数 start 与 end 会被解读为切片表示法。 如果 sub 未被找到则返回 -1。
j = raw.find('<') # find first'<' character
while j != -1:
k = raw.find('>', j + 1) # find next '>'
if k == -1:
return False
tag = raw[j + 1:k]
if not tag.startswith('/'):
S.push(tag)
else:
if S.is_empty():
return False
if tag[1:] != S.pop():
return False
j = raw.find('<', k + 1)
return S.is_empty()
def isMatchedHTML(raw):
# find "<" then find next ">", after that, get the tag if starting with / then it is the ending tag, pop.otherwise, it is starting tag,push into stack
S = ArrayStack()
i = raw.find("<") # this will find the first "<"
while i != -1:
j = raw.find(">", i + 1)
if j == -1:
return False
tag = raw[i + 1:j]
if not tag.startswith("/"):
S.push(tag)
else:
if S.is_empty():
return False
else:
if S.pop() != tag[1:]:
return False
i = raw.find("<", j + 1)
return S.is_empty()
def reverse_file(filename):
S = ArrayStack()
original = open(filename)
for line in original:
S.push(line.rstrip("\n"))
original.close()
output = open(filename, "w")
while not S.is_empty():
output.write(S.pop() + "\n")
output.close()
def reverse():
S = ArrayStack()
original = open(sys.argv[1])
for line in original:
S.push(line)
original.close()
output = open(sys.argv[1], 'w')
while not S.is_empty():
output.write(S.pop())
output.close()
def reverse_file(filename):
S = ArrayStack()
original = open(filename)
for line in original:
S.push(line.rstrip("\n"))
original.close()
output = open(filename, 'w')
while not S.is_empty():
output.write(S.pop() + "\n")
output.close()
def isMatchedHTML(raw):
# find "<" then find next ">", after that, get the tag if starting with / then it is the ending tag, pop.otherwise, it is starting tag,push into stack
S = ArrayStack()
i = raw.find("<") # this will find the first "<"
while i != -1:
j = raw.find(">", i + 1)
if j == -1:
return False
tag = raw[i + 1 : j]
if not tag.startswith("/"):
S.push(tag)
else:
if S.is_empty():
return False
else:
if S.pop() != tag[1:]:
return False
i = raw.find("<", j + 1)
return S.is_empty()
def closetags(html):
''' checks if all tags in a html block are closed '''
stack = Stack()
# is there an opening angle? find it
i = html.find('<')
while i != -1:
j = html.find('>', i + 1) # finding the next > character
if j == -1:
return False # invalid tag
tag = html[i + 1:j] # slice of the tag from html
if not tag.startswith('/'):
stack.push(tag) # its an opening tag, store in stack
else:
if stack.is_empty():
return False # closing tag found without an opening tag
if tag[1:] != stack.pop():
return False # mismatched tag
i = html.find('<', j + 1)
return stack.is_empty()
def reverse_file(filename):
""" Overwrite given file with its contents line-by-line reversed. """
S = ArrayStack()
original = open(filename)
for line in original:
S.push(line.rstrip('\n')) # we will re-insert newlines when writing
original.close()
# now we overwrite with contents in LIFO order
output = open(filename, 'w')
while not S.is_empty():
output.write(S.pop() + '\n')
output.close()
def reverse_file(filename):
""" overwrite given file with its contents line by line reversed """
S = ArrayStack()
original = open(filename)
for line in original:
S.push(line.rstrip('\n'))
original.close()
output = open(filename, "w")
while not S.is_empty():
output.write(S.pop() + "\n")
output.close()
def is_matched(string):
#创建一个栈
s = ArrayStack()
left = '{[('
right = '}])'
#遍历这个字符串
for c in string:
#如果c在left中则放入s中
if c in left:
s.push(c)
elif c in right:
if s.is_empty():
#如果c在栈中，但是栈却为空说明缺少左边的匹配 列如 ))、{)}、{[)]}
return False
#c在right中，拿c在right中的索引 和 栈顶元素在left中的索引做比较，并且移除栈顶元素。列如 (}、([})、[}]
if right.index(c) != left.index(s.pop()):
return False
#如果string为(( ，缺少右侧括号匹配，则栈不为空，返回false
return s.is_empty()
def isMatch(s):
left = "{[("
right = ")]}"
S = ArrayStack()
for c in s:
if c in left:
S.push(c)
elif c in right:
# what id didnt have before
# should check empty first
if S.is_empty():
return False
# if right.index(c) != left.index(S.pop())
# return False
cc = S.pop()
if not cc+c in ["{}","()","[]"]:
return False
else:
raise Exception("Invalid string")
if S.is_empty():
return True
else:
return False
def isMatch(s):
left = "{[("
right = ")]}"
S = ArrayStack()
for c in s:
if c in left:
S.push(c)
elif c in right:
# what id didnt have before
# should check empty first
if S.is_empty():
return False
# if right.index(c) != left.index(S.pop())
# return False
cc = S.pop()
if not cc + c in ["{}", "()", "[]"]:
return False
else:
raise Exception("Invalid string")
if S.is_empty():
return True
else:
return False
def print_reverse_order():
words_stack = ArrayStack()
stop = False
while not stop:
word = input('Please input a word: ').strip()
if word == 'stop':
stop = True
break
words_stack.push(word)
reverse = ''
while not words_stack.is_empty():
reverse += (f' {words_stack.pop()}')
print(f'Your words in reverse order: {reverse.lstrip()}')
def reverse():
''' replace the text in a file by a reverse of itself '''
stack = Stack()
# read original data into stack
with open('text.txt', 'r') as original:
for line in original:
stack.push(line.rstrip('\n'))
original.close()
# write data from stack to file
with open('text.txt', 'w') as output:
while not stack.is_empty():
output.write(stack.pop() + '\n')
output.close()
class PreorderIteratorStack(Generic[T]):
def __init__(self, root: BinaryTreeNode[K, I]) -> None:
self.stack = ArrayStack()
self.stack.push(root)
def __iter__(self):
return self
def __next__(self) -> T:
if self.stack.is_empty():
raise StopIteration
current = self.stack.pop()
if current.right is not None:
self.stack.push(current.right)
if current.left is not None:
self.stack.push(current.left)
return current.item
#!/usr/local/bin/python3.5
from stack import ArrayStack
theStack = ArrayStack()
theList = [1, 2, 4, 6, 8, 9, 12, 14, 16]
for item in theList:
theStack.push(item)
while not theStack.is_empty():
print(theStack.pop())
