def infixToPostfix(infixString):
order = {"*": 3, "/": 3, "+": 2, "-": 2, "(": 1}
operatorStack = Stack()
postfixString = []
infixList = infixString.split()
print infixList
for infixEle in infixList:
if infixEle in "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789":
print "append %s to the output string" % infixEle
postfixString.append(infixEle)
elif infixEle == "(":
print "push ( to the stack"
operatorStack.push(infixEle)
elif infixEle == ")":
print "pop operator until see ("
topOper = operatorStack.pop()
while topOper != "(":
print "pop %s until see (" % topOper
postfixString.append(topOper)
topOper = operatorStack.pop()
else:
while (not operatorStack.isEmpty()) and (order[operatorStack.peek()] >= order[infixEle]):
print "pop out %s before push %s in" % (operatorStack.peek(), infixEle)
postfixString.append(operatorStack.pop())
print "push %s in the stack" % infixEle
operatorStack.push(infixEle)
while not operatorStack.isEmpty():
postfixString.append(operatorStack.pop())
return postfixString
def parChecker(parString):
s = Stack()
for par in parString:
if par == "(":
s.push(par)
else:
if s.isEmpty():
return False
else:
s.pop()
return s.isEmpty()
def symChecker(symString):
s = Stack()
for sym in symString:
if sym in "({[":
s.push(sym)
else:
if s.isEmpty():
return False
else:
matSym = s.pop()
if not matchChecker(matSym,sym):
return False
return s.isEmpty()
def DecimalToBinary(decNum):
binString = ""
binStack = Stack()
while decNum > 0:
binNum = decNum % 2
binStack.push(binNum)
decNum = decNum // 2
while not binStack.isEmpty():
binString += str(binStack.pop())
return binString
def DecimalToBase(decNum, base):
system = "0123456789ABCDEF"
baseString = ""
baseStack = Stack()
while decNum > 0:
baseNum = decNum % base
baseStack.push(baseNum)
decNum = decNum // base
while not baseStack.isEmpty():
baseString += system[baseStack.pop()]
return baseString
