poj 3070 矩阵快速幂

这里有个链接大家可以学习一下，个人水平有限，很菜，怕说的不好误导大家

https://www.cnblogs.com/Konjakmoyu/p/4821044.html

 

#include<iostream>
#include<cstring>
using namespace std;

struct matrix
{
    int ss[2][2];
}a,b;

int mod = 10000;

//矩阵乘法
matrix multi(matrix a,matrix b)
{
    matrix temp;
    memset(temp.ss,0,sizeof(temp.ss));
    for(int i = 0;i<2;i++)
        for(int j = 0;j<2;j++)
            for(int k = 0;k<2;k++)
                temp.ss[i][j] = (temp.ss[i][j] + a.ss[i][k]*b.ss[k][j])%mod;
    return temp;
}

//矩阵快速幂
int fast_mod(int n)
{
    b.ss[0][0] = b.ss[0][1] = b.ss[1][0] = 1;
    b.ss[1][1] = 0;
    a.ss[0][0] = a.ss[1][1] = 1;
    a.ss[0][1] = a.ss[1][0] = 0;
    while(n)
    {
        if(n&1)
            a = multi(a,b);
        b = multi(b,b);
        n >>= 1;
    }
    return a.ss[0][0];
}

int main()
{
    int n;
    while(cin>>n&&n!=-1)
    {
        if(n == 0)    cout<<0<<endl;
        else cout<<fast_mod(n-1)<<endl;
    }
    return 0; 
}