Occult

Problem Description Tom has learned how to calculate the number of inversions in a permutation of n distinct objects by coding, his teacher gives him a problem: Give you a permutation of n distinc

Problem Description The counter-terrorists found a time bomb in the dust. But this time the terrorists improve on the time bomb. The number sequence of the time bomb counts from 1 to N. If the curr

Problem Description Vicky is a magician who loves math. She has great power in copying and creating. One day she gets an array {1}。 After that, every day she copies all the numbers in the arrays sh

Description 8是中国人很喜欢的一个数字，但是如果有3的存在就变成了38，就不是很好了。。 你能告诉我，在[L, R] 的正整数区间内，要么包含3 要么包含 8 的不同的整数有多少个么？ Input 第一行一个整数T (T ≤ 10000)，代表数据的组数 对于每组数据给两个整数 L, R (1 ≤ L ≤ R ≤ 1e9)

If we sum up every digit of a number and the result can be exactly divided by 10, we say this number is a good number.  You are required to count the number of good numbers in the range from A to B,