Hdu 1757A Simple Math Problem矩阵

构造个矩阵搞下就行了

a0 a1 a2 a3 a4 a5 a6 a7 a8 a9

1  0   0   0  0   0   0  0   0  0   

0  1   0   0  0   0   0  0   0  0    

0  0   1   0  0   0   0  0   0  0

0  0   0   1  0   0   0  0   0  0

0  0   0   0  1   0   0  0   0  0   

0  0   0   0  0   1   0  0   0  0

0  0   0   0  0   0   1  0   0  0

0  0   0   0  0   0   0  1   0  0

0  0   0   0  0   0   0  0   1  0

#include <cstdio>

#include <algorithm>

#include <iostream>

#include <string.h>

typedef long long LL;

using namespace std;

LL  vis[100];

LL  M;

struct Matrix

{

    LL  m[12][12];

};

LL  n;

Matrix Mul(Matrix a, Matrix b)

{

    Matrix ans;

    for (LL i = 0; i < 10; i++){

        for (LL j = 0; j < 10; j++){

            ans.m[i][j] = 0;

            for (LL k = 0; k < 10; k++){

                ans.m[i][j] += a.m[i][k] * b.m[k][j];

                ans.m[i][j] %= M;

            }

        }

    }

    return ans;

}



Matrix quick(Matrix a, LL b)

{

    Matrix ans;

    for (LL i = 0; i < 10; i++)

    for (LL j = 0; j < 10; j++)

        ans.m[i][j] = (i == j);

    while (b){

        if (b & 1) ans = Mul(ans, a);

        a = Mul(a, a);

        b >>= 1;

    }

    return ans;

}



Matrix init()

{

    for (LL i = 0; i < 10; i++)

        scanf("%d", &vis[i]);

    Matrix ans;

    for (LL i = 0; i < 10; i++)

    for (LL j = 0; j < 10; j++)

        ans.m[i][j] = 0;

    for (LL i = 0; i < 10; i++)

        ans.m[0][i] = vis[i];

    for (LL i = 1; i < 10; i++){

        ans.m[i][i - 1] = 1;

    }

    return ans;

}



void gao()

{

    LL t = n - 9;

    Matrix ans = init();

    ans = quick(ans, t);

    LL sum = 0;

    for (LL i = 0; i < 10; i++){

        sum += ans.m[0][i] * (9 - i);

        sum %= M;

    }

    cout << sum << endl;

}



int main()

{

    while (cin >> n >> M){

        if (n < 10){

            cout << n << endl;

            continue;

        }

        gao();

    }

    return 0;

}