#!/usr/bin/python3
# -*- coding:utf-8 -*-
'''
____ _ _ ____ _ _
|___ \| || | | _ \ ___ (_)_ __ | |_ ___
__) | || |_ | |_) / _ \| | '_ \| __/ __|
/ __/|__ _| | __/ (_) | | | | | |_\__ \\
|_____| |_| |_| \___/|_|_| |_|\__|___/
Given any four number in the range 1 to 10, which may have repetitions,
Using just the +, -, *, / operators; and the possible use of
brackets, (), show how to make an answer of 24.
An answer of "!" will generate a new set of four numbers (if your stuck).
Otherwise you are repeatedly asked for an expression until it evaluates to 24
Note: you cannot form multiple digit numbers from the supplied numbers,
so an answer of 12+12 when given 1, 2, 2, and 1 would not be allowed.
'''
from operator import mul, sub, add
import random
import sys
while True:
def choose4():
'four random digits >0 as characters'
return [random.randint(1,10) for i in range(4)]
def welcome():
print (__doc__)
print ('Try to input four numbers:\n e.g. 1 2 3 4\n\t')
nums=list(map(int, input().split(' ')))
print ("Your four number: " + " ".join(str(nums)))
return nums
def div(a,b):
if b==0:
return 999999.0
return a/b
def solve24(num, how,target):
global counts
ops ={mul:'*', div:'/', sub:'-', add:'+'}
if len(num)==1:
if round(num[0],5) ==round(target,5):
yield str(how[0]).replace(',', '').replace("'", '')
else:
for i, n1 in enumerate(num):
for j, n2 in enumerate(num):
if i!=j:
for op in ops:
new_num=[ n for k, n in enumerate(num) if k!=i and k!=j ] +[op(n1,n2)]
new_how=[h for k, h in enumerate(how) if k!=i and k!=j]+[(how[i], ops[op], how[j])]
counts+=1
print ("i= ", i, "; j= ", j, "; n1= ", n1, "; n2= ", n2, "\n new_num= ", new_num, "\tnew_how= ", new_how)
yield from solve24(new_num, new_how, target)
counts=0
nums = welcome()
if len(nums)!=4:
nums = choose4()
try:
print(next(solve24(nums, nums, 24)))
print('Total trys: ', counts)
break
except StopIteration:
print("!No solution found.")
print('Total trys: ', counts)
主要参考的https://rosettacode.org/wiki/24_game/Solve
对算法本身不是非常理解:
- 似乎没有考虑顺序问题, 即为什么[1,2,3,4]和[3,4,2,1]这样同样的数组上述算法一定能找到解;
- 如何加入乘方与开方以及阶乘运算.
