def copy(original_stack):
temp_list = []
copied_stock = Stack()
for i in original_stack:
temp_list.append(i)
for i in temp_list[::-1]:
copied_stock.push(i)
return copied_stock
def parentheses(test_str):
s = Stack()
for i in test_str:
if i in right_parenthesis:
s.push(i)
else:
pop = s.pop()
if not ord(pop) - ord(i) <= 2: # 比较ascii数值，小于等于2的话就是匹配的左括号
return False
return s.is_empty()
from algs4.Stack import Stack
test_str_list = '( ( 1 + 2 ) * ( ( 3 - 4 ) * ( 5 - 6 ) ) )'.split()
test_stock = Stack()
for i in test_str_list:
test_stock.push(i)
def copy(original_stack):
temp_list = []
copied_stock = Stack()
for i in original_stack:
temp_list.append(i)
for i in temp_list[::-1]:
copied_stock.push(i)
return copied_stock
print(copy(test_stock))
def __init__(self):
self.__right = Stack()
self.__left = Stack()
self.__N = 0
class Buffer:
def __init__(self):
self.__right = Stack()
self.__left = Stack()
self.__N = 0
def insert(self, c):
self.__right.push(c)
self.__N += 1
def delete(self):
self.__N -= 1
return self.__right.pop() if not self.__right.is_empty() else ''
def left(self, k):
for i in range(k):
if self.__left.is_empty():
return
self.__right.push(self.__left.pop())
def right(self, k):
for i in range(k):
if self.__right.is_empty():
return
self.__left.push(self.__right.pop())
def size(self):
return self.__N
from algs4.Stack import Stack
test_str = '( ( 1 + 2 ) * ( ( 3 - 4 ) * ( 5 - 6 ) ) )'
# test_str = '2 * 3 / ( 2 - 1 ) + 3 * ( 4 - 1 )'
test_str_list = test_str.split()
operator_stack = Stack()
numeric_stack = Stack()
operator_count = 0
number_count = 0
operator_precedence = {'+': 1, '-': 1, '*': 2, '/': 2}
res_str = ''
def not_greater(this, peek):
try:
a = operator_precedence[this]
b = operator_precedence[peek]
return True if a <= b else False
except KeyError:
return False
for i in test_str_list:
if i.isnumeric():
res_str += i + ' '
elif i == '(':
operator_stack.push(i)
elif i == ')':
while not operator_stack.is_empty() and operator_stack.peek() != '(':
res_str += operator_stack.pop() + ' '
operator_stack.pop()
from algs4.Stack import Stack
test_str = '1 + 2 ) * 3 - 4 ) * 5 - 6 ) ) )'
test_str_list = test_str.split()
res_stack = Stack()
num_count = 0
operator_count = 0
for i in test_str_list[::-1]:
res_stack.push(i)
if i.isnumeric():
num_count += 1
if num_count == 2:
num_count = 0
for j in range(operator_count):
res_stack.push('(')
operator_count = 0
elif i is not ')' and i is not ' ':
operator_count += 1
res_str = ''
for i in res_stack:
res_str += i + ' '
print(res_str)
from algs4.Stack import Stack
postfix_str = '1 2 + 3 4 - 5 6 - * *'
postfix_str_list = postfix_str.split()
numeric_stack = Stack()
operator_stack = Stack()
for i in postfix_str_list:
if i.isnumeric():
numeric_stack.push(i)
else:
res = 0
num2 = int(numeric_stack.pop())
num1 = int(numeric_stack.pop())
if i == '+':
res += num1 + num2
elif i == '-':
res += num1 - num2
elif i == '*':
res += num1 * num2
elif i == '/':
res += num1 / num2
numeric_stack.push(res)
print(numeric_stack.peek())
def __init__(self):
self._list_two_stack = [Stack(), Stack()]
# self.s1 = Stack()
# self.s2 = Stack()
self._N = 0