poj 3070 Fibonacci（矩阵快速幂）

Description

In the Fibonacci integer sequence, F₀ = 0, F₁ = 1, and F_n = F_{n ? 1} + F_{n ? 2} for n ≥ 2. For example, the first ten terms of the Fibonacci sequence are:

0, 1, 1, 2, 3, 5, 8, 13, 21, 34, …

An alternative formula for the Fibonacci sequence is

.

Given an integer n, your goal is to compute the last 4 digits of F_n.

Input

The input test file will contain multiple test cases. Each test case consists of a single line containing n (where 0 ≤ n ≤ 1,000,000,000). The end-of-file is denoted by a single line containing the number ?1.

Output

For each test case, print the last four digits of F_n. If the last four digits of F_n are all zeros, print ‘0’; otherwise, omit any leading zeros (i.e., print F_n mod 10000).

Sample Input

0
9
999999999
1000000000
-1

Sample Output

0
34
626
6875

代码：

#include 
#include 
#include 
using namespace std;

struct mat
{
    long long  t[2][2];
    void set()
    {
        memset(t,0,sizeof(t));
    }
}a,b;

mat multiple(mat a,mat b,int n,int p)
{
    int i,j,k;
    mat temp;
    temp.set();
    for(i=0;i>=1;
        b=multiple(b,b,2,p);
    }
    return a;
}
void init()
{
    a.t[0][0]=2;
    a.t[0][1]=1;
    a.t[1][0]=1;
    a.t[1][1]=0;
    b.t[0][0]=1;
    b.t[0][1]=1;
    b.t[1][0]=1;
    b.t[1][1]=0;
}
int main()
{
    int n;
    while(cin>>n)
    {
        if(n<0) break;
        init();
        a=quick_mod(a,b,n,10000);
        cout<<>