/* Sort a queue using two stacks */

queue_sort: /* Ascending sort */
    while (!queue.is_empty):
        elem = queue_dequeue;
        if stack1 is empty:
            stack1.push(elem);
        else:
            while (!stack1.is_empty && elem > stack1.top):
                stack2.push(stack1.pop)
            stack1.push(elem)
            while (!stack2.is_empty):
                stack1.push(stack2.pop)
    while (!stack1.is_empty):
        queue.enqueue(stack1.pop)