Python Basic data structure

Stack

Class Stack:    def __init__ (self):        self.items = []
    def isEmpty (self):        return Self.items = = []    def push (self, item):        self.items.append (item)    def pops (self ):        return Self.items.pop ()    def peek (self):        return Self.items[len (Self.items)-1]    def size (self) :        return len (self.items)

Queue

Class Queue:    def __init__ (self):        self.items = []    def isEmpty (self):        return Self.items = = []    def Enqueue (self, item):        Self.items.insert (0,item)    def dequeue (self):        return Self.items.pop ()    def size (self):        return len (self.items)

dual-ended queues

Class Deque:    def __init__ (self):        self.items = []    def isEmpty (self):        return Self.items = = []    def addfront (self, item):        self.items.append (item)    def addrear (self, item):        Self.items.insert (0,item )    def removefront (self):        return Self.items.pop ()    def removerear (self):        return Self.items.pop (0 )    def size (self):        return len (self.items)

Applicationparentheses match:

def check (s): Lefts = [' (', ' [') ', ' {']rights = [') ', '] ', '} ']stack = Stack () for C in S:if C in Lefts:stack.push (c) else:if s Tack.is_empty (): Return falsec_pop = Stack.pop () if Lefts.index (c_pop)! = Rights.index (c): Return Falseif Stack.is_empty: return Truereturn False

Binary Conversion

def divideBy2 (decnumber): Reback = Stack () while (Decnumber > 0): Reback.push (decnumber% 2) Decnumber = decnumber//2bins TR = ' While Not Reback.is_empty (): binstr = binstr + str (reback.pop ()) return binstrdef Baseconverter (Decnumber, base): ' Convert decimal number to arbitrary binary number ' digits = ' 0123456789ABCDEF ' reback = Stack () while (Decnumber > 0): Reback.push (decnumber% Base) Decnumber = decnumber//basebasestr = "While Not Reback.is_empty (): Basestr = Basestr + digits[reback.pop ()]return basest R

two stacks to implement a queue

# coding:utf-8from Pythonds.basic.stack Import Stackclass stactoqueue (object):d EF __init__ (self): Self.stack_one = Stack () Self.stack_two = Stack () def push (self, item): Self.stack_one.push (item) def pops (self): if Self.stack_two.isEmpty (): While not Self.stack_one.isEmpty (): Self.stack_two.push (Self.stack_one.pop ()) return Self.stack_two.pop () def size (self): return len (self.stack_one) + len (self.stack_two) def isEmpty (self): return self.size () = = 0if __name__ = = ' __main__ ': Queue = Stactoqueue () for X in range (5): Queue.push (x) for x in range (5):p rint (Queue.pop ())

Python Basic data structure