def simplify_linux_dir_path(path):
places = [p for p in path.split("/") if p != "." and p != ""]
s = Stack()
for p in places:
if p == ".." and not s.is_empty():
s.pop()
else:
s.push(p)
return "/" + '/'.join(s.get_list())
def build_lowest_number_removing_k_digits(num, k):
s = Stack()
l = len(num) - k
for c in num:
if not s.is_empty() and int(s.peek()) > int(c) and k > 0:
s.pop()
k -= 1
s.push(c)
return ''.join(s.get_list()[:l])