The number, 1406357289, is a 0 to 9 pandigital number because it is made up of each of the digits 0 to 9 in some order, but it also has a rather interesting sub-string divisibility property.

Let d₁ be the 1^st digit, d₂ be the 2^nd digit, and so on. In this way, we note the following:

d₂d₃d₄=406 is divisible by 2

d₃d₄d₅=063 is divisible by 3

d₄d₅d₆=635 is divisible by 5

d₅d₆d₇=357 is divisible by 7

d₆d₇d₈=572 is divisible by 11

d₇d₈d₉=728 is divisible by 13

d₈d₉d₁₀=289 is divisible by 17

Find the sum of all 0 to 9 pandigital numbers with this property.

趁周末有空+自己懒癌暂时没有发作，终于把最后2篇文章的迁移和评论的迁移弄好了。

不过写脚本弄评论迁移的时候发现，自己长久不写python，很多基础的东西又忘记了。

1. 读excel用应该是xlrd，这个以前还真没用过，不过用的方法很简单。最大的问题是xlrd的官网上不去()。不过用法倒和xlwt没差多少
2. datetime的用法又是各种查文档，看来这是一个习惯了，已经背不出了
3. timedelta的用法同上
4. json的dumps彻彻底底忘记了啊喂，记得当时用django写微信公众号后台还研究了好久unicode转换之类的
5. 原来最后想直接输出到文件的，但是居然unicode报错而且我还不想再折腾了……直接从console拷贝了，幸好也只有14条评论，要是14亿条就吓人了（哈哈想想也不可能）
6. 多说的parent_key是不能用还是我用错了格式……

代码记录如下:

#-*- coding: utf-8 -*-
import xlrd
import json
import datetime

result = {"posts": []}

data = xlrd.open_workbook('comments.xls')
table = data.sheets()[0]

nrows = table.nrows

for i in range(0, nrows):
    row_value = table.row_values(i)
    v = {
        "post_key": "post_%s" % int(row_value[0]),
        "author_name": row_value[1],
        "author_email": row_value[2],
        "created_at": (datetime.datetime.strptime(row_value[3], "%Y-%m-%d %H:%M:%S") + datetime.timedelta(hours=8)).strftime("%Y-%m-%d %H:%M:%S"),
        "message": row_value[4],
        "thread_key": "/blog/post/%s" % int(row_value[5])
    }
    if not row_value[6] == 'NULL':
        v["parent_key"] = "post_%s" % int(row_value[6])
    result["posts"].append(v)

out = json.dumps(result, ensure_ascii=False)
print out

参考：

多说导入格式

python datetime参考(各种慢，直接去别人家的博客找了)

xlrd Github仓库(其实没看，也是去别人家的博客找了)

The n^th term of the sequence of triangle numbers is given by, t_n = ½n(n+1); so the first ten triangle numbers are:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …

By converting each letter in a word to a number corresponding to its alphabetical position and adding these values we form a word value. For example, the word value for SKY is 19 + 11 + 25 = 55 = t₁₀. If the word value is a triangle number then we shall call the word a triangle word.

Using words.txt (right click and ‘Save Link/Target As…’), a 16K text file containing nearly two-thousand common English words, how many are triangle words?

We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once. For example, 2143 is a 4-digit pandigital and is also prime.

What is the largest n-digit pandigital prime that exists?

原来想自己用gimp弄个九宫格出来的，愣是发现gimp太（我）不（不）好（会）使（用）了，只能用了美图秀秀的在线版本工具出来，这么一整觉得自己好low啊……

小馄饨成为了最受我欢迎的早饭，张江手抓饼第二（没有拍但是我自己知道）烧麦第三

听说昨天早上github挂了，自从这个开始家里网络上github io就各种慢，好像被波及了？图片压缩成了jpg还是有大概3M大小，估计打开超级慢（如果其他人也被波及了的话），而且很模糊啊啊啊啊…………

想念微博的长微博工具

An irrational decimal fraction is created by concatenating the positive integers:

0.123456789101112131415161718192021…

It can be seen that the 12th digit of the fractional part is 1.

If d_n represents the nth digit of the fractional part, find the value of the following expression.

d₁ × d₁₀ × d₁₀₀ × d₁₀₀₀ × d₁₀₀₀₀ × d₁₀₀₀₀₀ × d_1000000

If p is the perimeter of a right angle triangle with integral length sides, {a,b,c}, there are exactly three solutions for p = 120.

{20,48,52}, {24,45,51}, {30,40,50}

For which value of p ≤ 1000, is the number of solutions maximised?