Clever Y

Little Y finds there is a very interesting formula in mathematics:

XY mod Z = K

Given X, Y, Z, we all know how to figure out K fast. However, given X, Z, K, could you figure out Y fast?

Input >>继续阅读

Discrete Logging

Given a prime P, 2 <= P < 231, an integer B, 2 <= B < P, and an integer N, 1 <= N < P, compute the discrete logarithm of N, base B, modulo P. That is, find an integer L such that

BL == N (mod P)

Input >>继续阅读

Mod Tree

Problem Description

The picture indicates a tree, every node has 2 children. >>继续阅读

1325 - Distributing Chocolates

InputNow as the result can be large, I asked for the result modulo 100 000 007 (a prime). But after that I found that this problem is easier than I thought. So, I changed the problem a little bit. I will give you the >>继续阅读