def twoNum(num1,num2,sign): #computer the result of two numbers
if sign=='/':
if num2!=0:
return num1/num2
else:
return 50000
else:
return eval(str(num1)+sign+str(num2))
def show(num1,num2,sign): #show the result of two numbers
print "%.1f %s %.1f = " % (num1,sign,num2),
def c24(numList):
sign=('+','-','*','/')
length=len(numList)
tempList=range(length-1) #get the result of two numbers, so the length minus 1
if length==2: #when there are only 2 numbers, computer directly!
n1=numList[0]
n2=numList[1]
for s in sign:
result1=twoNum(n1,n2,s)
result2=twoNum(n2,n1,s)
if result1==24.0:
show(n1,n2,s)
print "%.1f" % result1
return 1
elif result2==24.0:
show(n2,n1,s)
print "%.1f" % result2
return 1
return 0
else:
for i in range(length): #view all the possible collection of numbers
n1=numList[i]
for j in range(length):
if j!=i:
n2=numList[j]
temp=1
for k in range(length): #get the left numbers
if k!=i and k!=j:
tempList[temp]=numList[k]
temp+=1
for s in sign:
result=twoNum(n1,n2,s)
tempList[0]=result #the result is always put on position 0
if c24(tempList): #recurrent the number List
show(n1,n2,s)
print "%.1f" % result
return 1
return 0
numTuple=input("Please input 4 numbers to computer 24:(use ',' to divide them)")
numList=[float(i) for i in numTuple]
print "You input is : ", numList
if not c24(numList):
print "It is a mission impossible !"
程序不长，应该好懂，自己感觉是写的很烂的，还没摆脱c和c＋＋的风格，欠缺python的领悟，高手指点一下！
