poj 3070 Fibonacci（矩阵快速幂，简单）

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;

int num,mod=10000;
struct matrix
{
int a[2][2];
};

matrix multiply(matrix x,matrix y)//矩阵乘法
{
matrix temp;
for(int i=0;i<num;i++)
{
for(int j=0;j<num;j++)
{
int ans=0;
for(int k=0;k<num;k++)
{
ans+=((x.a[i][k]*y.a[k][j])%mod);
}
temp.a[i][j]=ans%mod;
}
}
return temp;
}

matrix calc(matrix origin,matrix answ,int n)//矩阵快速幂——answ*origin^n
{
while(n)
{
if(n%2==1)
answ=multiply(origin,answ);
origin=multiply(origin,origin);
n/=2;
}
return answ;
}

int main()
{

// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
int n;
while(scanf("%d",&n)!=EOF)
{
if(n==-1)break;
matrix origin= {0,1,
1,1};
matrix answ={0,0,
1,0};
num=2;
if(n==0||n==1)printf("%d\n",n);
else
{
answ=calc(origin,answ,n-1);
printf("%d\n",answ.a[1][0]);
}
}
return 0;
}