Number Sequence

Number Sequence

 

Time Limit: 1000ms   Memory limit: 65536K  有疑问？点这里^_^

题目描述

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).

输入

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.

输出

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

示例输入

1 1 3
1 2 10
0 0 0

示例输出

2
5

提示

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来源

 

示例程序

 

#include <stdio.h>
#include <stdlib.h>
long long int f[100000];
int main()
{
    int i,n,A,B;
    while(~scanf("%d%d%d",&A,&B,&n),A||B||n)
    {
        f[1] = 1;
        f[2] = 1;
        for(i=3; i<1000; i++)
        {
            f[i] = (A* f[i-1]+B*f[i-2])%7;
            if(f[i]==1&&f[i-1]==1)
            break;
        }
        n=n%(i-2);
        f[0]=f[i-2];
        printf("%lld\n",f[n]);
    }
    return 0;
}