def buildParseTree(fpexp):
fplist = fpexp.split()
pStack = Stack()
eTree = BinaryTree("")
pStack.push(eTree)
currentTree = eTree #入栈下降
for i in fplist:
if i == '(':
currentTree.insertLeft("")
pStack.push(currentTree)
currentTree = currentTree.getLeftChild() #入栈下降
elif i not in ['+', '-', '*', '/', ')']:
currentTree.setRootVal(int(i))
parent = pStack.pop()
currentTree = parent #出栈上升
elif i in ['+', '-', '*', '/']:
currentTree.setRootVal(i)
currentTree.insertRight("")
pStack.push(currentTree)
currentTree = currentTree.getRightChild() #入栈下降
elif i == ')':
currentTree = pStack.pop() #出栈上升
else:
raise ValueError
return eTree
def xiaoxiaole(strings):
s = Stack()
list = []
for str in strings: # 如果与栈顶相同则消去栈顶， 不同则压入栈顶
if str == s.peek():
s.remove()
else:
s.push(str)
if s.isEmpty():
return None
else:
while not s.isEmpty():
list.insert(0, s.pop()) # 取出栈中的每个元素，注意排列顺序
return "".join(list)
class Pin():
def __init__(self, name):
self.stack = Stack()
self.label = name
def name(self):
return self.label
def isEmpty(self):
return self.stack.isEmpty()
def check(self, d):
return self.stack.isEmpty() or d.get() < self.stack.peek().get()
def peek(self):
return self.stack.peek()
def push(self, d):
if self.check(d):
self.stack.push(d)
return True
else:
return False
def pop(self):
return self.stack.pop()
def __str__(self):
return self.name() + "=>" + str(self.stack)
def parChecker(sybomlString):
s = Stack()
balanced = True
index = 0
while index < len(sybomlString) and balanced:
symbol = sybomlString[index]
if symbol == '(':
s.push(symbol)
elif s.isEmpty():
balanced = False
else:
s.pop()
index += 1
if balanced and s.isEmpty():
return True
else:
return False
def divideBy2(decNumber):
remStack = Stack()
while decNumber > 0:
rem = decNumber % 2
remStack.push(rem)
decNumber = decNumber // 2
binString = ""
while not remStack.isEmpty():
binString = binString + str(remStack.pop())
return binString
def divideByN(decNumber, N=2):
digits = "0123456789ABCD"
remStack = Stack()
while decNumber > 0:
rem = decNumber % N
remStack.push(digits[rem])
decNumber = decNumber // N
binString = ""
while not remStack.isEmpty():
binString = binString + str(remStack.pop())
return binString
def parCheckers(sybomlString):
s = Stack()
balanced = True
index = 0
while index < len(sybomlString) and balanced:
symbol = sybomlString[index]
if symbol in '([{':
s.push(symbol)
elif s.isEmpty():
balanced = False
else:
top = s.pop()
if not matches(top, symbol):
return False
index += 1
if balanced and s.isEmpty():
return True
else:
return False
def infixTopostfix(infix):
prec = {"*": 3, "/": 3, "+": 2, "-": 2, "(": 1, ")": 1}
opstack = Stack()
postfixlist = []
infixlist = infix.split()
for token in infixlist:
if token in "ABCDEFGHIJKLMNOPQRSTUVWXYZ" or token in "0123456789":
postfixlist.append(token)
elif token == "(":
opstack.push(token)
elif token == ")":
toptoken = opstack.pop()
while toptoken != "(":
postfixlist.append(toptoken)
toptoken = opstack.pop()
else:
while (not opstack.isEmpty()
) and prec[opstack.peek()] >= prec[token]:
postfixlist.append(opstack.pop())
opstack.push(token)
while not opstack.isEmpty():
postfixlist.append(opstack.pop())
return " ".join(postfixlist)
def infixToPostfit(infiexpr):
prec = {}
prec['*'] = 3
prec['/'] = 3
prec['+'] = 2
prec['-'] = 2
prec['('] = 1
opStack = Stack()
postfitList = []
tokenList = infiexpr.split()
print(tokenList)
for token in tokenList:
if token in "ABCDEFG" or token in "0123456789":
postfitList.append(token)
elif token == '(':
opStack.push(token)
elif token == ')':
topToken = opStack.pop()
while topToken != '(':
postfitList.append(topToken)
topToken = opStack.pop()
else:
while (not opStack.isEmpty()) and (prec[opStack.peek()] >=
prec[token]):
postfitList.append(opStack.pop())
opStack.push(token)
while not opStack.isEmpty():
postfitList.append(opStack.pop())
return " ".join(postfitList)
import sys
sys.path.append('../')
from basic.stack import Stack
s = Stack()
print(s.isEmpty())
s.push(4)
s.push('dog')
print(s.peek())
s.push(True)
print(s.size())
print(s.isEmpty())
s.push(8.4)
print(s.pop())
print(s.pop())
print(s.size())
def __init__(self, name):
self.stack = Stack()
self.label = name
def setUp(self):
self.stack = Stack()
class TestStack(TestCase):
def setUp(self):
self.stack = Stack()
def test_is_empty(self):
# stack = Stack()
self.assertTrue(self.stack.is_empty())
def test_size(self):
self.assertEqual(0, self.stack.size())
def test_pop(self):
# stack = Stack()
self.stack.push(1)
self.assertEqual(1, self.stack.pop())
def test_top(self):
self.stack.push(1)
self.stack.push(2)
self.assertEqual(2, self.stack.top())
def test_push(self):
self.stack.push(1)
self.assertEqual(1, self.stack.pop())