hdu1005

maksyuki 发表于 oj 分类,标签:
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Number Sequence

Problem Description

A number sequence is defined as follows:

f(1) = 1, f(2) = 1, f(n) = (A * f(n - 1) + B * f(n - 2)) mod 7.

Given A, B, and n, you are to calculate the value of f(n).

Input

The input consists of multiple test cases. Each test case contains 3 integers A, B and n on a single line (1 <= A, B <= 1000, 1 <= n <= 100,000,000). Three zeros signal the end of input and this test case is not to be processed.

Output

For each test case, print the value of f(n) on a single line.

Sample Input

1 1 3

1 2 10

0 0 0

Sample Output

2

5

Author

CHEN, Shunbao

Source

ZJCPC2004

 

题目类型:循环节

算法分析:由于n比较大,直接使用矩阵快速幂会TLE。这里发现所有的序列的循环节的长度都是48,所以可以直接预打出前48个数的表,然后直接查表