algorithms/algorithms/stack/is_sorted.py at master · pk210700/algorithms · GitHub

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"""

Given a stack, a function is_sorted accepts a stack as a parameter and returns

true if the elements in the stack occur in ascending increasing order from

bottom, and false otherwise. That is, the smallest element should be at bottom

For example:

bottom [6, 3, 5, 1, 2, 4] top

The function should return false

bottom [1, 2, 3, 4, 5, 6] top

The function should return true

"""

def is_sorted(stack):

storage_stack = []

for i in range(len(stack)):

if len(stack) == 0:

break

first_val = stack.pop()

if len(stack) == 0:

break

second_val = stack.pop()

if first_val < second_val:

return False

storage_stack.append(first_val)

stack.append(second_val)

# Backup stack

for i in range(len(storage_stack)):

stack.append(storage_stack.pop())

return True