poj 3070 Fibonacci 矩阵快速幂

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 2;
const int mod = 10000;
struct matrix
{
int arr

;
matrix operator *(matrix a) /*重载*号，矩阵乘法*/
{
matrix b;
memset(b.arr, 0, sizeof b.arr);
for(int i = 0; i < 2; i++)
for(int j = 0; j < 2; j++)
for(int k = 0; k < 2; k++)
b.arr[i][j] = (b.arr[i][j] + arr[i][k] * a.arr[k][j]) % mod;
return b;
}
};
matrix matrix_fast_pow(int n, matrix a)
{
matrix res;
memset(res.arr, 0, sizeof res.arr);
for(int i = 0; i < 2; i++) /*初始化为单位矩阵*/
res.arr[i][i] = 1;
while(n)
{
if(n & 1) res = res * a;
a = a * a;
n >>= 1;
}
return res;
}
int main()
{
int n;
while(scanf("%d", &n), n != -1)
{
matrix tmp;
tmp.arr[0][0] = tmp.arr[0][1] = tmp.arr[1][0] = 1;
tmp.arr[1][1] = 0;
matrix res = matrix_fast_pow(n, tmp);
printf("%d\n", res.arr[0][1] % mod);
}
}