杭电hdu_1005_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 31 2 100 0 0

 

Sample Output

25

 

<pre name="code" class="cpp">#include<memory>#include<iostream>#include<string>//#include<QPainter>//#include<fstream>#include<cctype>#include<algorithm>#include<cmath>#include<map>using namespace std;int fun(int &a,int &b,int n){    if(n == 1) return 1;    if(n == 2) return 1;    if(n>2){        return ( a*fun(a,b,n-1) + b*fun(a,b,n-2) )%7 ;    }}int main(int argc, char *argv[]){    int a,b,n;    while(cin >> a >> b >> n)    {        if(!a && !b && !n) break;        int i = fun(a,b,n%49);        cout << i << endl;    }    return 0;}