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()