def check_bal_par(par_str):
if not len(par_str):
return True
if len(par_str) % 2 != 0:
return False
s = Stack()
for item in par_str:
if s.is_empty():
s.push(item)
else:
if s.peek() == '(' and item == ')':
s.pop()
else:
s.push(item)
return s.is_empty()
def test_pop(self):
my_stack = Stack(5)
my_stack.push(2)
my_stack.push(3)
x = my_stack.pop()
self.assertEqual(x, 3, "should be 3")
self.assertEqual(my_stack.top, 0, "should be 0")
def reverse(string):
myStack = Stack(len(string))
for i in string:
myStack.push(i)
result = ""
while not myStack.isEmpty():
result += myStack.pop()
return result
def dtob(decimal, base = 2):
myStack = Stack()
while decimal > 0:
myStack.push(decimal % base)
decimal //= base # 나머지
result = ""
while not myStack.isEmpty():
result += str(myStack.pop())
return result
def parseParenthesis(string):
balanced = 1
index = 0
myStack = Stack(len(string))
while (index < len(string)) and (balanced == 1):
check = string[index]
if check == "(":
myStack.push(check)
else:
if myStack.isEmpty():
balanced = 0
else:
myStack.pop()
index += 1
if balanced == 1 and myStack.isEmpty():
return True
else:
return False
def addTwoNumbers(l1, l2):
l1_node = l1
stack1 = Stack()
while l1_node:
stack1.push(l1_node.val)
l1_node = l1_node.next
l2_node = l2
stack2 = Stack()
while l2_node:
stack2.push(l2_node.val)
l2_node = l2_node.next
result = ListNode(None)
s = 0
while stack1.size() > 0 and stack2.size() > 0:
num1 = stack1.pop()
num2 = stack2.pop()
node = ListNode(((num1 + num2 + s) % 10))
node.next = result.next
result.next = node
s = int((num1 + num2 + s) / 10)
stack = stack1 if stack1.size() > 0 else stack2
while stack.size() > 0:
num = stack.pop()
node = ListNode(((num + s) % 10))
node.next = result.next
result.next = node
s = int((num + s) / 10)
if s > 0:
node = ListNode(s)
node.next = result.next
result.next = node
return result.next
def is_valid(self, s):
array_stack = Stack()
str_list = list(s)
for index, char in enumerate(str_list):
if char == '(' or char == '{' or char == '[':
array_stack.push(char)
else:
if array_stack.is_empty():
return False
top_char = array_stack.pop()
if char == ')' and top_char != '(':
return False
if char == ']' and top_char != '[':
return False
if char == '}' and top_char != '{':
return False
return array_stack.is_empty()
from stack.Stack import Stack
__author__ = 'lijiayan'
if __name__ == '__main__':
s = Stack()
s.push(1)
s.push(2)
s.push(3)
for i in range(s.size()):
print(s.pop())
print("栈大小：" + str(s.size()))
