Fibonacci

Fibonacci

留一个矩阵快速幂模板。

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

typedef long long ll;
struct matrix
{
    ll m[2][2];
}res,base;
const int mod = 10000;

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

ll quick_pow(ll n)
{
    res.m[0][0] = 1,res.m[0][1] = 0;
    res.m[1][0] = 0,res.m[1][1] = 1;
    base.m[0][0] = 1,base.m[0][1]=  1;
    base.m[1][0] = 1,base.m[1][1] = 0;
    while(n)
    {
        if(n%2) res = multi(res,base);
        n /= 2;
        base = multi(base,base);
    }
    return res.m[0][1];
}
int main()
{
    ll n;
    while(cin>>n)
    {
        if(n==-1) break;
        cout<<quick_pow(n)<<endl;
    }
    return 0;
}