模板題

|pn+1    pn|

|pn     pn-1|

[0][1]位置是pn的值，套個矩陣快速冪的板子，因為要取後四位，要mod 10000。

#include<iostream>
#include<string>
#include<cstdio>
#include<cstring>
#include<queue>
#include<map>
#include<cmath>
#include<stack>
#include<set>
#include<vector>
#include<algorithm>
#define LL long long
#define inf 1<<30
using namespace std;
const int MAXN=2;
const int mod=10000;
struct Matrix
{
	int mat[MAXN][MAXN];
	Matrix() {}
	Matrix operator*(Matrix const &b)const
	{
		Matrix res;
		memset(res.mat, 0, sizeof(res.mat));
		for (int i = 0 ;i < MAXN; i++)
			for (int j = 0; j < MAXN; j++)
				for (int k = 0; k < MAXN; k++)
					res.mat[i][j] = (res.mat[i][j]+this->mat[i][k] * b.mat[k][j])%mod;
		return res;
	}
};
Matrix pow_mod(Matrix base, int n)
{
	Matrix res;
	memset(res.mat, 0, sizeof(res.mat));
	for (int i = 0; i < MAXN; i++)
		res.mat[i][i] = 1;
	while (n > 0)
	{
		if (n & 1) res = res*base;
		base = base*base;
		n >>= 1;
	}
	return res;
}
int main()
{
    int n;
    Matrix base;
    base.mat[0][0]=1;
    base.mat[0][1]=1;
    base.mat[1][0]=1;
    base.mat[1][1]=0;
    while(~scanf("%d",&n))
    {
        if(n==-1) break;
        Matrix ans=pow_mod(base,n);
        printf("%d\n",ans.mat[0][1]);
    }
}