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# 3.6 Write a program to sort a stack in ascending order (with biggest items on top). You may use at most one additional stack to hold items, but you may not copy the elements into any other data structure (such as an array).The stack supports the following operations: push, pop, peek, and isEmpty.


from stack import Stack

def sort(stack):
    result = Stack()
    while stack.isEmpty() is not True:
        tmp = stack.pop()
        while result.isEmpty() is not True and result.peek() > tmp:

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# cc 3.5 Implement a MyQUeue class which implements a queue using two stacks

from stack import Stack

class MyQueue:

    def __init__(self):
        self.inque = Stack()
        self.outque = Stack()

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# cc 3.4 Tower of Hanoi

from stack import Stack, Node

class tower:
    
    def __init__(self):
        self.start = Stack()
        self.dest = Stack()
        self.buff = Stack()

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# 3.3 set of stacks

from stack import Stack, Node

class SetOfStacks:

    def  __init__(self, limit):  
        self.last = Stack()
        self.limit = limit
        self.stacklist = [self.last]

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#3.2  How would you design a stack which, in addition to push and pop, also has a function min which returns the minimum element? Push, pop and min should all operate in O(1) time.

from stack import Stack, Node

class stackmin(Stack):

    def __init__(self):
        Stack.__init__(self)
        self.min = Stack()
        self.minItem = None

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#stack structure in python 

class Node:
    
    def __init__(self,item):
        self.item = item
        self.next = None


class Stack:     

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# 2.6 Given a circular linked list, implement an algorithm which returns the node at the beginning of the loop.
#slower and faster pointers

from LinkedList import Node, LinkedList

def findloop(ls):
    p1 = ls.head
    p2 = ls.head
    if p2 is None or p2.next is None:
        return null

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#cc 2.5 addition with reverse digit


from LinkedList import Node, LinkedList


def  addReverse(ls1, ls2):
    
    add1 = ls1.head
    add2 = ls2.head

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#2.4    prtition a linked list around a value x, such that all nodes less than x come before all nodes greater than or equal to x.
#creat two list, <x & >= x, merge them at last


from LinkedList import LinkedList, Node

def partition(self, x):
    if self is None:
        return
    small = LinkedList()

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#2.3 Implement an algorithm to delete a node in the middle of a singly linked list, given only access to that node.

from LinkedList import LinkedList, Node

def deleteNode(node):
    if node is None or node.next is None:
        return False
    node.data = node.next.data
    node.next = node.next.next
    return True