矩阵快速幂 求斐波那契第N项

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

const int M = 1e9+;

struct Matrix {
    long long a[][];
    Matrix() {
        memset(a, , sizeof(a));
    }
    Matrix operator * (const Matrix y) {
        Matrix ans;
        for(int i = ; i <= ; i++)
            for(int j = ; j <= ; j++)
                for(int k = ; k <= ; k++)
                    ans.a[i][j] += a[i][k]*y.a[k][j];
        for(int i = ; i <= ; i++)
            for(int j = ; j <= ; j++)
                ans.a[i][j] %= M;
        return ans;
    }
    void operator = (const Matrix b) {
        for(int i = ; i <= ; i++)
            for(int j = ; j <= ; j++)
                a[i][j] = b.a[i][j];
    }
};

int solve(long long x) {
    Matrix ans, trs;
    ans.a[][] = ans.a[][] = ;
    trs.a[][] = trs.a[][] = trs.a[][] = ;
    while(x) {
        if(x&)
            ans = ans*trs;
        trs = trs*trs;
        x >>= ;
    }
    return ans.a[][];
}

int main() {
    int n;
    scanf("%d", &n);
    cout << solve(n-) << endl;
    return ;
}

POJ 3070