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 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 s = Stack() print(s.get_size()) print(s.is_empty()) print(s.peek()) s.print_stack() s.push(5) s.push(2) s.push(28) s.push(11) s.push(18) print(s.get_size()) print(s.is_empty()) print(s.peek()) s.print_stack() print(s.pop()) print(s.pop()) print(s.pop()) print(s.pop()) print(s.pop()) s.print_stack()
