class MyQueue: def __init__(self): self.queue = Stack() def add(self, item): self.queue.push(item) def remove(self): temp = self.queue.reverse() res = temp.pop() self.queue = temp.reverse() return res def peek(self): temp = self.queue.reverse() res = temp.peek() self.queue = temp.reverse() return res def is_empty(self): return self.queue.is_empty() def __str__(self): return str(self.queue)
def pop_at(self, index):
if index > self.piles.size()-1:
raise "Invalid index."
temp_stack = Stack()
for i in range(index, 0, -1):
temp_stack.push(SetOfStacks.pop_stack(self))
item = self.piles.pop()
self._backfill(temp_stack.reverse(), self.piles)
return item.pop()
