pythonalgorithms/algorithms/stack/ordered_stack.py at master · lowpolyness/pythonalgorithms

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# The stack remains always ordered such that the highest value

# is at the top and the lowest at the bottom

class OrderedStack:

def __init__(self):

self.items = []

def is_empty(self):

return self.items == []

def push_t(self, item):

self.items.append(item)

# push method to maintain order when pushing new elements

def push(self, item):

temp_stack = OrderedStack()

if self.is_empty() or item > self.peek():

self.push_t(item)

else:

while item < self.peek() and not self.is_empty():

temp_stack.push_t(self.pop())

self.push_t(item)

while not temp_stack.is_empty():

self.push_t(temp_stack.pop())

def pop(self):

if self.is_empty():

raise IndexError("Stack is empty")

return self.items.pop()

def peek(self):

return self.items[len(self.items) - 1]

def size(self):

return len(self.items)