## poj3187

maksyuki 发表于 oj 分类，标签: ,

Backward Digit Sums

FJ and his cows enjoy playing a mental game. They write down the numbers from 1 to N (1 <= N <= 10) in a certain order and then sum adjacent numbers to produce a new list with one fewer number. They repeat this until only >>继续阅读

## poj3421

maksyuki 发表于 oj 分类，标签: ,

X-factor Chains

Given a positive integer X, an X-factor chain of length m is a sequence of integers, 1 = X0, X1, X2, …, Xm = X satisfying Xi < Xi+1 and Xi | Xi+1 where a | b means a perfectly divides into b. Now we are interested in the maximum >>继续阅读

## poj2992

maksyuki 发表于 oj 分类，标签:

Divisors

Your task in this problem is to determine the number of divisors of Cnk. Just for fun -- or do you need any special reason for such a useful computation?

Input

The input consists of several instances. Each instance consists of a single >>继续阅读

## poj1496

maksyuki 发表于 oj 分类，标签:

Word Index

Encoding schemes are often used in situations requiring encryption or information storage/transmission economy. Here, we develop a simple encoding scheme that encodes particular types of words with five or fewer (lower case) letters as i >>继续阅读

## lightoj1140

maksyuki 发表于 oj 分类，标签:

1140 - How Many Zeroes?

InputJimmy writes down the decimal representations of all natural numbers between and including m and n, (m ≤ n). How many zeroes will he write down?

Input starts with an integer T (≤ 11000), denoting the number of test ca >>继续阅读