2010puzzle.py

#! -*- coding:utf-8 -*-

# RPN
# 1 2 _ 3 _ 4 _ 5 _ 6 _ 7 _ 8 _ 9 _
c = [i for i in range(1,3)]

def select(cc, n):
    #print cc
    c1 = cc

    if len(c1) >= 9 + 8:
        a = calc(c1)
        if a == 2010:
            print "-- 2010=",c1
            #import sys
            #sys.exit()
        return
    if n < 10:
        select(c1+[n], n+1)
    if len(c1) < (n-1) * 2:
        select(c1+['+'], n)
        select(c1+['-'], n)
        select(c1+['*'], n)
        select(c1+['/'], n)

def calc(cc):
    """
    計算
    >>> a = calc([1, 2, '+'])
    >>> a
    3.0
    >>> a = calc([1, 2, '+', 3, '-'])
    >>> a
    0.0
    """
    calcList = []
    for c in cc:
        try:
            if c == '+':
                calcList[-2] = calcList[-2] + calcList[-1]
            if c == '/':
                try:
                    calcList[-2] = calcList[-2] / calcList[-1]
                except ZeroDivisionError:
                    return -1
            if c == '-':
                calcList[-2] = calcList[-2] - calcList[-1]
            if c == '*':
                calcList[-2] = calcList[-2] * calcList[-1]
        except IndexError:
            return -1
        if isinstance(c,int):
            calcList.append(float(c))
        else:
            calcList.pop()
        #print calcList
    return calcList[0]

if __name__ == "__main__":
    import doctest
    doctest.testmod()
    select(c,3)