Number Sequence

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)

Total Submission(s): 124827 Accepted Submission(s): 30331

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

数据很大，所以肯定有循环节

#include <iostream>

#include <cstdio>

using namespace std;

int Arr[10000];

int main()

{

    int a,b,i;

    int  n;

    Arr[1]=1;

    Arr[2]=1;

    while(cin>>a>>b>>n)

    {

        if(!a&&!b&&!n)

        {

            break;

        }

        for( i=3; i<10000; i++)

        {

            Arr[i]=(a*Arr[i-1]+b*Arr[i-2])%7;

            if(Arr[i]==1&&Arr[i-1]==1)

            {

                break;

            }

        }

        n=n%(i-2);

        Arr[0]=Arr[i-2];

        cout<<Arr[n]<<endl;

    }

    return 0;

}

版权声明：本文为博主原创文章，未经博主允许不得转载。