Question

对于给定的数字列表（input.txt）我正在尝试使用output.txt打印出与每行关联的循环的数字和长度。

所以我到现在为止：

/input.txt看起来有点像这样：

4 6

2 11

3 20

等...

计算周期长度的函数：

def calc_cycle(number):
count = 1
while number != 1:
    if number % 2 != 0:
        number = number * 3 + 1
    else:
        number = number / 2
    count = count + 1
return count

计算最大周期的函数：

def max_cycle(n, m):
    max_value=1
    for i in range(n, m+1):
        x = calc_cycle(i)
        if max_value < x:
            max_value = x
    return n, m, max_value

一个读取input.txt文件并解析值的函数：

def read_input(list_of_urls):
    with open(list_of_urls) as f:
        for line in f:
            #n,m = [int(i) for i in line.split(' ')]
            n,m = line.split(' ')
            n=int(n)
            m=int(m)
            print n,m

基本上我被困在这个部分，我不知道如何得到一个看起来像这样的output.txt文件：

4 6 9  #9 being the max cycle for all the numbers between 4 and 9
2 11 20 #20 being the max cycle for all numbers between 2 and 11 
3 20 21 #21 being the max cycle for numbers between 3 and 20

请指导！？

Answer 1

string formating

def read_input(list_of_urls):
    with open(list_of_urls) as f, open('output.txt', 'w+') as f2:
        for line in f:
            n,m = line.split(' ')
            n=int(n)
            m=int(m)
            _,_,thisMaxCycle = max_cycle(n,m)
            f2.write("{0} {1} {2} #{2} being the max cycle for all numbers between {0} and {1}\n".format(n,m,thisMaxCycle))

python 3 * n + 1 - 计算一个数字列表的最长周期

1 个答案: