问Python数字组合生成器需要是递归的
EN

Stack Overflow用户

提问于 2017-12-25 05:12:38

回答 2查看 111关注 0票数 1

我一直试图使这个组合函数递归，但似乎无法弄清楚。我有一个可以正常工作的非递归版本，它可以做我想做的事情，但它是一个静态函数，我需要它是动态的，因为直到运行时我才知道有多少嵌套的级别。如果有人能把我送到正确的方向，我将不胜感激！

def Combinations(p, n):

    for i in range(len(n)):
        print(n[i])

    for i in range(len(n)):
        for j in range(i+1, len(n)):
            print(n[i], n[j])

    for i in range(len(n)):
        for j in range(i+1, len(n)):
            for k in range(j+1, len(n)):
                print(n[i], n[j], n[k])


def main():
    pools = 3
    numbers = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
    print("{} pools for numbers {}\n".format(pools, numbers))
    Combinations(pools, numbers)


main()

#########################输出###############################

python

recursion

回答 2

Stack Overflow用户

回答已采纳

发布于 2017-12-25 05:31:46

当你准备大量数据时，递归不是一个好主意。

更简单的解决方案：(非递归)

import itertools

def Combinations(p, n):
    result = []
    for _ in xrange(1, p+1):
        keywords = itertools.product(n, repeat =_)
        for each in keywords:
            result.append(" ".join(str(_) for _ in each))
    return result

def main():
    pools = 3
    numbers = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
    print("{} pools for numbers {}\n".format(pools, numbers))
    print (Combinations(pools, numbers))


main()

输出：

3 pools for numbers (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

/*
* 提示：该行代码过长，系统自动注释不进行高亮。一键复制会移除系统注释 
* ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '1 1', '1 2', '1 3', '1 4', '1 5', '1 6', '1 7', '1 8', '1 9', '1 10', '2 1', '2 2', '2 3', '2 4', '2 5', '2 6', '2 7', '2 8', '2 9', '2 10', '3 1', '3 2', '3 3', '3 4', '3 5', '3 6', '3 7', '3 8', '3 9', '3 10', '4 1', '4 2', '4 3', '4 4', '4 5', '4 6', '4 7', '4 8', '4 9', '4 10', '5 1', '5 2', '5 3', '5 4', '5 5', '5 6', '5 7', '5 8', '5 9', '5 10', '6 1', '6 2', '6 3', '6 4', '6 5', '6 6', '6 7', '6 8', '6 9', '6 10', '7 1', '7 2', '7 3', '7 4', '7 5', '7 6', '7 7', '7 8', '7 9', '7 10', '8 1', '8 2', '8 3', '8 4', '8 5', '8 6', '8 7', '8 8', '8 9', '8 10', '9 1', '9 2', '9 3', '9 4', '9 5', '9 6', '9 7', '9 8', '9 9', '9 10', '10 1', '10 2', '10 3', '10 4', '10 5', '10 6', '10 7', '10 8', '10 9', '10 10', '1 1 1', '1 1 2', '1 1 3', '1 1 4', '1 1 5', '1 1 6', '1 1 7', '1 1 8', '1 1 9', '1 1 10', '1 2 1', '1 2 2', '1 2 3', '1 2 4', '1 2 5', '1 2 6', '1 2 7', '1 2 8', '1 2 9', '1 2 10', '1 3 1', '1 3 2', '1 3 3', '1 3 4', '1 3 5', '1 3 6', '1 3 7', '1 3 8', '1 3 9', '1 3 10', '1 4 1', '1 4 2', '1 4 3', '1 4 4', '1 4 5', '1 4 6', '1 4 7', '1 4 8', '1 4 9', '1 4 10', '1 5 1', '1 5 2', '1 5 3', '1 5 4', '1 5 5', '1 5 6', '1 5 7', '1 5 8', '1 5 9', '1 5 10', '1 6 1', '1 6 2', '1 6 3', '1 6 4', '1 6 5', '1 6 6', '1 6 7', '1 6 8', '1 6 9', '1 6 10', '1 7 1', '1 7 2', '1 7 3', '1 7 4', '1 7 5', '1 7 6', '1 7 7', '1 7 8', '1 7 9', '1 7 10', '1 8 1', '1 8 2', '1 8 3', '1 8 4', '1 8 5', '1 8 6', '1 8 7', '1 8 8', '1 8 9', '1 8 10', '1 9 1', '1 9 2', '1 9 3', '1 9 4', '1 9 5', '1 9 6', '1 9 7', '1 9 8', '1 9 9', '1 9 10', '1 10 1', '1 10 2', '1 10 3', '1 10 4', '1 10 5', '1 10 6', '1 10 7', '1 10 8', '1 10 9', '1 10 10', '2 1 1', '2 1 2', '2 1 3', '2 1 4', '2 1 5', '2 1 6', '2 1 7', '2 1 8', '2 1 9', '2 1 10', '2 2 1', '2 2 2', '2 2 3', '2 2 4', '2 2 5', '2 2 6', '2 2 7', '2 2 8', '2 2 9', '2 2 10', '2 3 1', '2 3 2', '2 3 3', '2 3 4', '2 3 5', '2 3 6', '2 3 7', '2 3 8', '2 3 9', '2 3 10', '2 4 1', '2 4 2', '2 4 3', '2 4 4', '2 4 5', '2 4 6', '2 4 7', '2 4 8', '2 4 9', '2 4 10', '2 5 1', '2 5 2', '2 5 3', '2 5 4', '2 5 5', '2 5 6', '2 5 7', '2 5 8', '2 5 9', '2 5 10', '2 6 1', '2 6 2', '2 6 3', '2 6 4', '2 6 5', '2 6 6', '2 6 7', '2 6 8', '2 6 9', '2 6 10', '2 7 1', '2 7 2', '2 7 3', '2 7 4', '2 7 5', '2 7 6', '2 7 7', '2 7 8', '2 7 9', '2 7 10', '2 8 1', '2 8 2', '2 8 3', '2 8 4', '2 8 5', '2 8 6', '2 8 7', '2 8 8', '2 8 9', '2 8 10', '2 9 1', '2 9 2', '2 9 3', '2 9 4', '2 9 5', '2 9 6', '2 9 7', '2 9 8', '2 9 9', '2 9 10', '2 10 1', '2 10 2', '2 10 3', '2 10 4', '2 10 5', '2 10 6', '2 10 7', '2 10 8', '2 10 9', '2 10 10', '3 1 1', '3 1 2', '3 1 3', '3 1 4', '3 1 5', '3 1 6', '3 1 7', '3 1 8', '3 1 9', '3 1 10', '3 2 1', '3 2 2', '3 2 3', '3 2 4', '3 2 5', '3 2 6', '3 2 7', '3 2 8', '3 2 9', '3 2 10', '3 3 1', '3 3 2', '3 3 3', '3 3 4', '3 3 5', '3 3 6', '3 3 7', '3 3 8', '3 3 9', '3 3 10', '3 4 1', '3 4 2', '3 4 3', '3 4 4', '3 4 5', '3 4 6', '3 4 7', '3 4 8', '3 4 9', '3 4 10', '3 5 1', '3 5 2', '3 5 3', '3 5 4', '3 5 5', '3 5 6', '3 5 7', '3 5 8', '3 5 9', '3 5 10', '3 6 1', '3 6 2', '3 6 3', '3 6 4', '3 6 5', '3 6 6', '3 6 7', '3 6 8', '3 6 9', '3 6 10', '3 7 1', '3 7 2', '3 7 3', '3 7 4', '3 7 5', '3 7 6', '3 7 7', '3 7 8', '3 7 9', '3 7 10', '3 8 1', '3 8 2', '3 8 3', '3 8 4', '3 8 5', '3 8 6', '3 8 7', '3 8 8', '3 8 9', '3 8 10', '3 9 1', '3 9 2', '3 9 3', '3 9 4', '3 9 5', '3 9 6', '3 9 7', '3 9 8', '3 9 9', '3 9 10', '3 10 1', '3 10 2', '3 10 3', '3 10 4', '3 10 5', '3 10 6', '3 10 7', '3 10 8', '3 10 9', '3 10 10', '4 1 1', '4 1 2', '4 1 3', '4 1 4', '4 1 5', '4 1 6', '4 1 7', '4 1 8', '4 1 9', '4 1 10', '4 2 1', '4 2 2', '4 2 3', '4 2 4', '4 2 5', '4 2 6', '4 2 7', '4 2 8', '4 2 9', '4 2 10', '4 3 1', '4 3 2', '4 3 3', '4 3 4', '4 3 5', '4 3 6', '4 3 7', '4 3 8', '4 3 9', '4 3 10', '4 4 1', '4 4 2', '4 4 3', '4 4 4', '4 4 5', '4 4 6', '4 4 7', '4 4 8', '4 4 9', '4 4 10', '4 5 1', '4 5 2', '4 5 3', '4 5 4', '4 5 5', '4 5 6', '4 5 7', '4 5 8', '4 5 9', '4 5 10', '4 6 1', '4 6 2', '4 6 3', '4 6 4', '4 6 5', '4 6 6', '4 6 7', '4 6 8', '4 6 9', '4 6 10', '4 7 1', '4 7 2', '4 7 3', '4 7 4', '4 7 5', '4 7 6', '4 7 7', '4 7 8', '4 7 9', '4 7 10', '4 8 1', '4 8 2', '4 8 3', '4 8 4', '4 8 5', '4 8 6', '4 8 7', '4 8 8', '4 8 9', '4 8 10', '4 9 1', '4 9 2', '4 9 3', '4 9 4', '4 9 5', '4 9 6', '4 9 7', '4 9 8', '4 9 9', '4 9 10', '4 10 1', '4 10 2', '4 10 3', '4 10 4', '4 10 5', '4 10 6', '4 10 7', '4 10 8', '4 10 9', '4 10 10', '5 1 1', '5 1 2', '5 1 3', '5 1 4', '5 1 5', '5 1 6', '5 1 7', '5 1 8', '5 1 9', '5 1 10', '5 2 1', '5 2 2', '5 2 3', '5 2 4', '5 2 5', '5 2 6', '5 2 7', '5 2 8', '5 2 9', '5 2 10', '5 3 1', '5 3 2', '5 3 3', '5 3 4', '5 3 5', '5 3 6', '5 3 7', '5 3 8', '5 3 9', '5 3 10', '5 4 1', '5 4 2', '5 4 3', '5 4 4', '5 4 5', '5 4 6', '5 4 7', '5 4 8', '5 4 9', '5 4 10', '5 5 1', '5 5 2', '5 5 3', '5 5 4', '5 5 5', '5 5 6', '5 5 7', '5 5 8', '5 5 9', '5 5 10', '5 6 1', '5 6 2', '5 6 3', '5 6 4', '5 6 5', '5 6 6', '5 6 7', '5 6 8', '5 6 9', '5 6 10', '5 7 1', '5 7 2', '5 7 3', '5 7 4', '5 7 5', '5 7 6', '5 7 7', '5 7 8', '5 7 9', '5 7 10', '5 8 1', '5 8 2', '5 8 3', '5 8 4', '5 8 5', '5 8 6', '5 8 7', '5 8 8', '5 8 9', '5 8 10', '5 9 1', '5 9 2', '5 9 3', '5 9 4', '5 9 5', '5 9 6', '5 9 7', '5 9 8', '5 9 9', '5 9 10', '5 10 1', '5 10 2', '5 10 3', '5 10 4', '5 10 5', '5 10 6', '5 10 7', '5 10 8', '5 10 9', '5 10 10', '6 1 1', '6 1 2', '6 1 3', '6 1 4', '6 1 5', '6 1 6', '6 1 7', '6 1 8', '6 1 9', '6 1 10', '6 2 1', '6 2 2', '6 2 3', '6 2 4', '6 2 5', '6 2 6', '6 2 7', '6 2 8', '6 2 9', '6 2 10', '6 3 1', '6 3 2', '6 3 3', '6 3 4', '6 3 5', '6 3 6', '6 3 7', '6 3 8', '6 3 9', '6 3 10', '6 4 1', '6 4 2', '6 4 3', '6 4 4', '6 4 5', '6 4 6', '6 4 7', '6 4 8', '6 4 9', '6 4 10', '6 5 1', '6 5 2', '6 5 3', '6 5 4', '6 5 5', '6 5 6', '6 5 7', '6 5 8', '6 5 9', '6 5 10', '6 6 1', '6 6 2', '6 6 3', '6 6 4', '6 6 5', '6 6 6', '6 6 7', '6 6 8', '6 6 9', '6 6 10', '6 7 1', '6 7 2', '6 7 3', '6 7 4', '6 7 5', '6 7 6', '6 7 7', '6 7 8', '6 7 9', '6 7 10', '6 8 1', '6 8 2', '6 8 3', '6 8 4', '6 8 5', '6 8 6', '6 8 7', '6 8 8', '6 8 9', '6 8 10', '6 9 1', '6 9 2', '6 9 3', '6 9 4', '6 9 5', '6 9 6', '6 9 7', '6 9 8', '6 9 9', '6 9 10', '6 10 1', '6 10 2', '6 10 3', '6 10 4', '6 10 5', '6 10 6', '6 10 7', '6 10 8', '6 10 9', '6 10 10', '7 1 1', '7 1 2', '7 1 3', '7 1 4', '7 1 5', '7 1 6', '7 1 7', '7 1 8', '7 1 9', '7 1 10', '7 2 1', '7 2 2', '7 2 3', '7 2 4', '7 2 5', '7 2 6', '7 2 7', '7 2 8', '7 2 9', '7 2 10', '7 3 1', '7 3 2', '7 3 3', '7 3 4', '7 3 5', '7 3 6', '7 3 7', '7 3 8', '7 3 9', '7 3 10', '7 4 1', '7 4 2', '7 4 3', '7 4 4', '7 4 5', '7 4 6', '7 4 7', '7 4 8', '7 4 9', '7 4 10', '7 5 1', '7 5 2', '7 5 3', '7 5 4', '7 5 5', '7 5 6', '7 5 7', '7 5 8', '7 5 9', '7 5 10', '7 6 1', '7 6 2', '7 6 3', '7 6 4', '7 6 5', '7 6 6', '7 6 7', '7 6 8', '7 6 9', '7 6 10', '7 7 1', '7 7 2', '7 7 3', '7 7 4', '7 7 5', '7 7 6', '7 7 7', '7 7 8', '7 7 9', '7 7 10', '7 8 1', '7 8 2', '7 8 3', '7 8 4', '7 8 5', '7 8 6', '7 8 7', '7 8 8', '7 8 9', '7 8 10', '7 9 1', '7 9 2', '7 9 3', '7 9 4', '7 9 5', '7 9 6', '7 9 7', '7 9 8', '7 9 9', '7 9 10', '7 10 1', '7 10 2', '7 10 3', '7 10 4', '7 10 5', '7 10 6', '7 10 7', '7 10 8', '7 10 9', '7 10 10', '8 1 1', '8 1 2', '8 1 3', '8 1 4', '8 1 5', '8 1 6', '8 1 7', '8 1 8', '8 1 9', '8 1 10', '8 2 1', '8 2 2', '8 2 3', '8 2 4', '8 2 5', '8 2 6', '8 2 7', '8 2 8', '8 2 9', '8 2 10', '8 3 1', '8 3 2', '8 3 3', '8 3 4', '8 3 5', '8 3 6', '8 3 7', '8 3 8', '8 3 9', '8 3 10', '8 4 1', '8 4 2', '8 4 3', '8 4 4', '8 4 5', '8 4 6', '8 4 7', '8 4 8', '8 4 9', '8 4 10', '8 5 1', '8 5 2', '8 5 3', '8 5 4', '8 5 5', '8 5 6', '8 5 7', '8 5 8', '8 5 9', '8 5 10', '8 6 1', '8 6 2', '8 6 3', '8 6 4', '8 6 5', '8 6 6', '8 6 7', '8 6 8', '8 6 9', '8 6 10', '8 7 1', '8 7 2', '8 7 3', '8 7 4', '8 7 5', '8 7 6', '8 7 7', '8 7 8', '8 7 9', '8 7 10', '8 8 1', '8 8 2', '8 8 3', '8 8 4', '8 8 5', '8 8 6', '8 8 7', '8 8 8', '8 8 9', '8 8 10', '8 9 1', '8 9 2', '8 9 3', '8 9 4', '8 9 5', '8 9 6', '8 9 7', '8 9 8', '8 9 9', '8 9 10', '8 10 1', '8 10 2', '8 10 3', '8 10 4', '8 10 5', '8 10 6', '8 10 7', '8 10 8', '8 10 9', '8 10 10', '9 1 1', '9 1 2', '9 1 3', '9 1 4', '9 1 5', '9 1 6', '9 1 7', '9 1 8', '9 1 9', '9 1 10', '9 2 1', '9 2 2', '9 2 3', '9 2 4', '9 2 5', '9 2 6', '9 2 7', '9 2 8', '9 2 9', '9 2 10', '9 3 1', '9 3 2', '9 3 3', '9 3 4', '9 3 5', '9 3 6', '9 3 7', '9 3 8', '9 3 9', '9 3 10', '9 4 1', '9 4 2', '9 4 3', '9 4 4', '9 4 5', '9 4 6', '9 4 7', '9 4 8', '9 4 9', '9 4 10', '9 5 1', '9 5 2', '9 5 3', '9 5 4', '9 5 5', '9 5 6', '9 5 7', '9 5 8', '9 5 9', '9 5 10', '9 6 1', '9 6 2', '9 6 3', '9 6 4', '9 6 5', '9 6 6', '9 6 7', '9 6 8', '9 6 9', '9 6 10', '9 7 1', '9 7 2', '9 7 3', '9 7 4', '9 7 5', '9 7 6', '9 7 7', '9 7 8', '9 7 9', '9 7 10', '9 8 1', '9 8 2', '9 8 3', '9 8 4', '9 8 5', '9 8 6', '9 8 7', '9 8 8', '9 8 9', '9 8 10', '9 9 1', '9 9 2', '9 9 3', '9 9 4', '9 9 5', '9 9 6', '9 9 7', '9 9 8', '9 9 9', '9 9 10', '9 10 1', '9 10 2', '9 10 3', '9 10 4', '9 10 5', '9 10 6', '9 10 7', '9 10 8', '9 10 9', '9 10 10', '10 1 1', '10 1 2', '10 1 3', '10 1 4', '10 1 5', '10 1 6', '10 1 7', '10 1 8', '10 1 9', '10 1 10', '10 2 1', '10 2 2', '10 2 3', '10 2 4', '10 2 5', '10 2 6', '10 2 7', '10 2 8', '10 2 9', '10 2 10', '10 3 1', '10 3 2', '10 3 3', '10 3 4', '10 3 5', '10 3 6', '10 3 7', '10 3 8', '10 3 9', '10 3 10', '10 4 1', '10 4 2', '10 4 3', '10 4 4', '10 4 5', '10 4 6', '10 4 7', '10 4 8', '10 4 9', '10 4 10', '10 5 1', '10 5 2', '10 5 3', '10 5 4', '10 5 5', '10 5 6', '10 5 7', '10 5 8', '10 5 9', '10 5 10', '10 6 1', '10 6 2', '10 6 3', '10 6 4', '10 6 5', '10 6 6', '10 6 7', '10 6 8', '10 6 9', '10 6 10', '10 7 1', '10 7 2', '10 7 3', '10 7 4', '10 7 5', '10 7 6', '10 7 7', '10 7 8', '10 7 9', '10 7 10', '10 8 1', '10 8 2', '10 8 3', '10 8 4', '10 8 5', '10 8 6', '10 8 7', '10 8 8', '10 8 9', '10 8 10', '10 9 1', '10 9 2', '10 9 3', '10 9 4', '10 9 5', '10 9 6', '10 9 7', '10 9 8', '10 9 9', '10 9 10', '10 10 1', '10 10 2', '10 10 3', '10 10 4', '10 10 5', '10 10 6', '10 10 7', '10 10 8', '10 10 9', '10 10 10']
*/

票数 1

Stack Overflow用户

发布于 2017-12-25 05:40:04

你这是在重新发明轮子。您可以使用itertools包中的combinations函数来获得您想要的内容。

from itertools import combinations

def all_combos(max_depth, iterable):
    return [list(combinations(iterable, d)) for d in range(1, max_depth+1)]

pools = 3
numbers = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

all_combos(pools, numbers)

或者如果你真的想要一个打印版本：

def all_combos_print(max_depth, iterable):
    for d in range(1, max_depth+1):
        for c in combinations(iterable, d):
            print(('{} '*len(c)).format(*c))

all_combos_print(4, range(5))
# prints:
0
1
2
3
4
0 1
0 2
0 3
0 4
1 2
1 3
1 4
2 3
2 4
3 4
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
0 1 2 3
0 1 2 4
0 1 3 4
0 2 3 4
1 2 3 4