Number Sequence
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 43278 Accepted Submission(s): 9449
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
Sample Output
2 5
//第一版，直接暴力递归，超时
#include<iostream>
using namespace std;
long long int fac(int A, int B, int n)
{
if (n == 1 || n == 2)
return 1;
else
return (A * fac(A,B,n - 1) + B * fac(A,B,n - 2)) % 7;
}
int main()
{
int A, B, n;
while (cin >> A >> B >> n&&A != 0 && B != 0 && n != 0)
{
cout << fac(A, B, n % 48) << endl;
}
return 0;
}
HDU（1005）Number Sequence
原文：https://www.cnblogs.com/gcter/p/9738661.html
