def parCheckerMore(symbol_string):
"""
通用括号匹配,支持 (, [, { 这三种
@symbol_string: 要匹配的括号字符串
@return: 返回匹配结果,bool类型
"""
stack = Stack()
index = 0
balanced_flag = True # 两边括号数量平衡标识
while index < len(symbol_string) and balanced_flag:
symbol = symbol_string[index]
# 判断左边括号类型需要调整
if symbol in '([{':
stack.push(symbol)
else:
if stack.isEmpty():
balanced_flag = False
else:
top = stack.pop()
# 栈中移除的括号要和进入栈的括号匹配类型
if not matches(top, symbol):
balanced_flag = False
index += 1
if balanced_flag and stack.isEmpty():
balanced_flag = True
else:
balanced_flag = False
return balanced_flag
def parChecker(symbol_string):
"""
先写一个只有'()'类型的算法
@symbol_string: 要匹配的括号字符串
@return: 返回匹配结果,bool类型
"""
stack = Stack()
index = 0
balanced_flag = True # 两边括号数量平衡标识
while index < len(symbol_string) and balanced_flag:
symbol = symbol_string[index]
if symbol == '(':
stack.push(symbol)
else:
if stack.isEmpty():
balanced_flag = False
else:
stack.pop()
index += 1
if balanced_flag and stack.isEmpty():
balanced_flag = True
else:
balanced_flag = False
return balanced_flag
def infixToPostfix(infixExpr):
"""
中缀表达式转后缀表达式算法实现
@infixExpr: 中缀表达式,格式如:A + B * C,必须含空格,且操作数只包含A-Z 0-9其中的值
@return: 转换成功的后缀表达式
"""
# 记录操作符优先级
prec = {}
prec["*"] = 3
prec["/"] = 3
prec["+"] = 2
prec["-"] = 2
prec["("] = 1
op_stack = Stack()
possible_str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
post_fix_lst = []
token_lst = infixExpr.split()
for token in token_lst:
# 如果单词是 操作数, 则直接添加到后缀表达式列表的末尾
if token in possible_str:
post_fix_lst.append(token)
# 如果单词是左'(', 则压入栈顶,标记下
elif token == '(':
op_stack.push(token)
# 如果单词是右')',则反复弹出栈顶操作符,加入到输出列表末尾,直到遇到左括号
elif token == ')':
top_token = op_stack.pop()
while top_token != '(':
post_fix_lst.append(top_token)
top_token = op_stack.pop()
# 如果单词是操作符, 则压入栈顶,
# 但在压之前, 要比较其与栈顶操作符的优先级
# 如果栈顶操作符的优先级高于它, 就要反复弹出栈顶操作符, 加入到输出列表末尾
# 直到栈顶操作符的优先级低于它
else:
# 注意条件prec[op_stack.peek()] >= prec[token], 不是 > ,是 >=,因为+- 或*/是同一级
while (not op_stack.isEmpty()) and (prec[op_stack.peek()] >=
prec[token]):
post_fix_lst.append(op_stack.pop())
op_stack.push(token)
# 扫描结束后,把opstack栈中的所有剩余操作符依次弹出,加入到输出列表末尾
# 把输出列表再用join()合并成后缀表达式字符串
while not op_stack.isEmpty():
post_fix_lst.append(op_stack.pop())
return " ".join(post_fix_lst)
def convert_to_base(self, base):
decimal = self.a
s = Stack()
while decimal > 0:
decimal, remender = divmod(decimal, base)
s.push(remender)
n = ""
while not s.isEmpty():
n += Digit.digits[s.pop()]
self.a = n
def divideBy2(decNumber):
"""
10进制数转2进制
@num: 需要转换的数
@return: 转换后的结果
"""
remainder_stack = Stack()
while decNumber > 0:
remainder = decNumber % 2
remainder_stack.push(remainder)
decNumber //= 2 # 整除
result = ''
while not remainder_stack.isEmpty():
result += str(remainder_stack.pop())
return result
def baseConvert(decNumber, base):
"""
10进制数转成任意16进制以下的数
@decNumber: 需要转换的数
@base: 进制
@return: 转换后的结果
"""
digits = '0123456789ABCDEF' # 定义数范围(最大16进制)
remainder_stack = Stack()
while decNumber > 0:
remainder = decNumber % base
remainder_stack.push(remainder)
decNumber //= base # 整除
result = ''
while not remainder_stack.isEmpty():
result += digits[remainder_stack.pop()]
return result
