Number Sequence

Number Sequence

Time Limit: 1000ms   Memory limit: 65535K  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 31 2 100 0 0

示例输出

25

来源

ZJCPC2004

#include<stdio.h>    int main()    {        int i,j,n,m,k,t,f1,f2,f3;        while(scanf("%d %d %d",&n,&m,&k)&&(n||m||k))        {            f1=1;            f2=1;            if(k==1)                printf("%d\n",f1);            if(k==2)                printf("%d\n",f2);            if(k>=3)            {                for(i=3;i<=k;i++)                {                    f3=(f2*n+f1*m)%7;                    f1=f2;                    f2=f3;                }                printf("%d\n",f3);            }        }    }