def generalized_balanced_checker(
tokens: str,
supported_symbols: dict = {
"opens": "({[",
"closes": ")}]"
}) -> bool:
"""
Write an algorithm that will read a string of supported_symbols from left to
right and decide whether the symbols are balanced
"""
idx: int = 0
s = Stack()
balanced: bool = True
def is_closing(top_symbol, closing_symbol):
return supported_symbols["opens"].index(
top_symbol) == supported_symbols["closes"].index(closing_symbol)
while idx < len(tokens):
symbol = tokens[idx]
if symbol in supported_symbols["opens"]:
s.push(symbol)
else:
if s.is_empty():
balanced = False
else:
top_symbol = s.pop()
if not is_closing(top_symbol, symbol):
balanced = False
idx += 1
if balanced and s.is_empty():
return True
else:
return False
def test__stack_operations__ok(self):
s = Stack()
s.push(10)
assert s.size() == 1
assert s.peek() == 10
s.push(22)
assert s.size() == 2
assert s.peek() == 22
assert s.is_empty() == False
s.pop()
assert s.size() == 1
s.pop()
assert s.size() == 0
assert s.is_empty() == True
def balanced_parens_checker(tokens: str) -> bool:
"""
Write an algorithm that will read a string of parentheses from left to
right and decide whether the symbols are balanced
"""
idx: int = 0
s = Stack()
balanced: bool = True
while idx < len(tokens):
symbol = tokens[idx]
if symbol == "(":
s.push(symbol)
else:
if s.is_empty():
balanced = False
else:
s.pop()
idx += 1
if balanced and s.is_empty():
return True
else:
return False
def divide_by_2(num: int) -> str:
"""
Takes an interger and returns its equivalent in binary
"""
s = Stack()
binary_str: str = ""
if num == 0:
s.push(num)
while num > 0:
num, remainder = divmod(num, 2)
s.push(remainder)
while not s.is_empty():
digit = s.pop()
binary_str += str(digit)
return binary_str
def base_converter(num: int, base: int) -> str:
"""
Ref: http://calc.50x.eu/
"""
stack = Stack()
converted_str: str = ""
digits = "0123456789ABCDEF"
if num == 0:
stack.push(num)
while num > 0:
num, remainder = divmod(num, base)
stack.push(remainder)
while not stack.is_empty():
digit = stack.pop()
converted_str += digits[digit]
return converted_str
def test__new_stack__is_empty(self):
s = Stack()
assert s.size() == 0
assert s.is_empty() == True
assert s.peek() == None
