Occult

Problem DescriptionTom was on the way home from school. He saw a matrix in the sky. He found that if we numbered rows and columns of the matrix from 0, then,ai,j=Cjiif i ai,j=0Tom sudden

Problem DescriptionTired of playing computer games, alpc23 is planning to play a game on numbers. Because plus and subtraction is too easy for this gay, he wants to do some multiplication in a num

Problem DescriptionThere are 5 distinct binary trees of 3 nodes:Let T(n) be the number of distinct non-empty binary trees of no more than n nodes, your task is to calculate T(n) mod m.In

Problem DescriptionGiven a number sequence A1,A2....An,indicating N=∏ni=1iAi.What is the product of all the divisors of N? InputThere are multiple test cases.First line of each c

DescriptionThe modular modular multiplicative inverse of an integer a modulo m is an integer x such that a-1≡x (mod m). This is equivalent toax≡1 (mod m).InputThere are multiple test

Problem Description度熊手上有一本字典存储了大量的单词，有一次，他把所有单词组成了一个很长很长的字符串。现在麻烦来了，他忘记了原来的字符串都是什么，神奇的是他竟然记得原来那些字符串的哈希值。一个字符串的哈希值，由以下公式计算得到：H(s)=∏i≤len(s)i=1(Si−28) (mod 9973)Si代表 S[i] 字符的 ASCII 码。请

Problem Description有一个无限大的矩形，初始时你在左上角（即第一行第一列），每次你都可以选择一个右下方格子，并瞬移过去（如从下图中的红色格子能直接瞬移到蓝色格子），求到第n行第m列的格子有几种方案，答案对1000000007取模。![http://acm.hdu.edu.cn/data/images/C702-1003-1.jpg](http://acm.hdu.

DescriptionIn the Republic of Remoteland, the people celebrate their independence day every year. However, as it was a long long time ago, nobody can remember when it was exactly. The only thing p