勿躁

  汝有田舍翁,家资殷盛,而累世不识“之”“乎”。一岁,聘楚士训其子,楚士始训之搦管临朱,书一画,训曰“一”字;书二画,训曰“二”字;书三画,训曰“三”字。其子辄欣欣然,掷笔归告其父曰:“儿得矣,儿得矣;可无烦先生矣,重费馆谷也,请谢去。”其父喜,从之,具币谢遣楚士。
  逾时,其父拟征召姻友万氏姓者饮,令子晨起治状,久之不成,父趣之。其子恚曰:“天下姓字伙矣,奈何姓万,自晨至今,才完五百画也。”
  初机士偶一解,而即以訑訑自矜有得。殆类是已。

应谐录》刘元卿


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【思维/模拟】Self Numbers

 

传送门:POJ1316
In 1949 the Indian mathematician D.R. Kaprekar discovered a class of numbers called self-numbers. For any positive integer n, define d(n) to be n plus the sum of the digits of n. (The d stands for digitadition, a term coined by Kaprekar.) For example, d(75) = 75 + 7 + 5 = 87. Given any positive integer n as a starting point, you can construct the infinite increasing sequence of integers n, d(n), d(d(n)), d(d(d(n))), …. For example, if you start with 33, the next number is 33 + 3 + 3 = 39, the next is 39 + 3 + 9 = 51, the next is 51 + 5 + 1 = 57, and so you generate the sequence
33, 39, 51, 57, 69, 84, 96, 111, 114, 120, 123, 129, 141, …

The number n is called a generator of d(n). In the sequence above, 33 is a generator of 39, 39 is a generator of 51, 51 is a generator of 57, and so on. Some numbers have more than one generator: for example, 101 has two generators, 91 and 100. A number with no generators is a self-number. There are thirteen self-numbers less than 100: 1, 3, 5, 7, 9, 20, 31, 42, 53, 64, 75, 86, and 97.

Write a program to output all positive self-numbers less than or equal 1000000 in increasing order, one per line.

继续阅读【思维/模拟】Self Numbers

SDAU训练日志第58篇(2019年2月14日)

这两天因为家里有事跟着家里出门了。在酒店做题好苦涩,等明天回家再把这两天做过的题目写成题解。不得不说,昨天的思维题超级好玩。。但是今天的线段树就emmmm了,写起来挺生疏的,还是得多练习。

另外,这破地方的包车因为人变少了结果只有开学前两天才组织,原来的早班车没有了,,只能晚回学校了。。

学校那还攒着一堆事没处理,还有万恶的两篇读书笔记,qtmd,回去估计要忙上半天,烦。

一回学校估计就要准备五月的省赛了,剩下的这一个多星期,加油加油!

【思维】Purification

You are an adventurer currently journeying inside an evil temple. After defeating a couple of weak zombies, you arrived at a square room consisting of tiles forming an n × n grid. The rows are numbered 1 through n from top to bottom, and the columns are numbered 1 through n from left to right. At the far side of the room lies a door locked with evil magical forces. The following inscriptions are written on the door:

The cleaning of all evil will awaken the door!
Being a very senior adventurer, you immediately realize what this means. You notice that every single cell in the grid are initially evil. You should purify all of these cells. 继续阅读【思维】Purification