Number Sequence

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 173150    Accepted Submission(s): 42786

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

# include <stdio.h>
# include <string>int fun(int a, int b, int n){
    if (n==1)
        return 1;
    else if(n==2)
        return 1;
    else
        return (a*fun(a, b, n-1)+b*fun(a, b, n-2))%7;
}

int main(){
    int a, b, n;
    while(scanf("%d%d%d",&a,&b,&n)){
        if(a == 0 && b == 0 && n == 0)
            break;
        else
        printf("%d\n",fun(a, b, n%49));
    }
    system("pause");
    return 0;
}

Hdu 1005 Number Sequence