24dian.py

用python编写的24点程序

#!/usr/bin/python
import psyco ; psyco.full()
from psyco.classes import *
import math
import os
import sys
import numarray

if len(sys.argv) > 1:
    num24 = float(sys.argv[1])
else:
    num24 = 24.0

def oper(aa, bb, op):
    a, b = float(aa), float(bb)
    if op == 1:
        return [a+b,'+',1]
    elif op == 2:
        return [a-b,'-',1]
    elif op == 3:
        return [a*b,'*',2]
    else:
        if b == 0:
            return [1E8,'error',2]
        else:
            return [a/b,'/',2]

def dostep(li, lstr, ops):
    global num24
    if len(li) == 1 and abs(float(li[0])-num24) < 1E-4:
        print lstr[0],"=",int(num24)
        sys.exit()
    for i in range(0, len(li)-1):
        for op in range(1,5):
            op_res = oper(li[i], li[i+1], op)
            if op_res[1] == 'error':
                break
            newli = []
            newli = li[0:i]
            newli.append(op_res[0])
            newli.extend(li[i+2:])
            newstr = []
            newstr = lstr[0:i]
            if op_res[2] > ops[i]:
                tmplstr = "(" + lstr[i] + ")"
            else:
                tmplstr = lstr[i][:]
            if op_res[2] > ops[i+1]:
                tmprstr = "(" + lstr[i+1] + ")"
            else:
                tmprstr = lstr[i+1][:]
            newstr.append(tmplstr+op_res[1]+tmprstr)
            newstr.extend(lstr[i+2:])
            newop = []
            newop = ops[0:i]
            newop.append(op_res[2])
            newop.extend(ops[i+2:])
            dostep(newli, newstr, newop)

def insert_all(ele, li):
    if len(li) == 0:
        return [[ele]]
    tli = []
    for each_li in insert_all(li[0],li[1:]):
        for i in range(0, len(li)+1):
            newli=each_li[:]
            newli.insert(i, ele)
            tli.append(newli)
    return tli

def all(li):
    return insert_all(li[0], li[1:])

def uni(li):
    ifFind = True
    while ifFind:
        ifFind = False
        for i in range(len(li)):
            if li.index(li[i]) != i:
                ifFind = True
                li.remove(li[i])
                break
    return li

inputline = raw_input('Enter the numbers:')
numbers = inputline.split()
allnum = uni(all(numbers))
for li in allnum:
    str = li[:]
    ops = list(numarray.zeros((len(li),)) + 10)
    dostep(li, str, ops)
print "No answer"