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
答案：
#include <stdio.h>
int main(int argc, char* argv[])
{
 int A, B, n;
 int res[100], k = 0;
 int r[100];
 while (true)
 {
  scanf("%d %d %d", &A, &B, &n);
  if (A ==0&&B==0&&n==0)
   break;
  if (n == 1 || n == 2)
   res[k++] = 1;
  else
  {
   r[1] = 1, r[2] = 1;
   for (int i = 3; i < 100; ++i)
   {
    r[i] = (A*r[i-1]+B*r[i-2])%7;
    if (r[i-1] == 1 && r[i] == 1)
     break;
   }
   n = n%(i-2);
   if (n == 0)
    res[k++] = r[i-2];
   else
    res[k++] = r[n];
  }
 }
 for (int i = 0; i < k; ++i)
  printf("%d/n", res[i]);
 return 0;
}