记录编号	584894	评测结果	AAAAAAAAAA
题目名称	[HZOI 2016]简单的AVL树	最终得分	100
用户昵称	┭┮﹏┭┮	是否通过	通过
代码语言	C++	运行时间	0.000 s
提交时间	2023-11-16 20:05:36	内存使用	0.00 MiB

#include <bits/stdc++.h> 
using namespace std;
typedef long long ll; 
//矩阵快速幂 
ll n,p;
struct Matrix{
    ll a[3][3],n,m;
    void clear(){n = m = 0;memset(a,0,sizeof(a));}
    Matrix operator * (const Matrix &x)const{
        Matrix y;y.clear();
        y.n = n,y.m = m;
        for(int i = 0;i < n;i++)
            for(int j = 0;j < m;j++)
                for(int k = 0;k < m;k++)
                    y.a[i][j] = (y.a[i][j] + (a[i][k] * x.a[k][j]) % p) % p;
        return y;
    }
}c,f;
int main(){
    freopen("AVL.in","r",stdin);
    freopen("AVL.out","w",stdout);
    scanf("%lld%lld",&n,&p);
    if(n == 1){printf("1\n");return 0;}
    if(n == 2){printf("2\n");return 0;}
    n -= 2;
    
    f.n = 1,f.m = 3;
    f.a[0][0] = 2,f.a[0][1] = 1,f.a[0][2] = 1;
    c.n = 3,c.m = 3;
    c.a[0][0] = 1,c.a[1][0] = 1,c.a[2][0] = 1,c.a[0][1] = 1,c.a[2][2] = 1;
    while(n){
        if(n & 1)f = f * c;
        c = c * c;
        n >>= 1;
    }
    printf("%lld\n",f.a[0][0]);
    
    return 0;
    
}