luogu3390 【模板】矩阵快速幂

#include <iostream>
#include <cstdio>
using namespace std;
typedef long long ll;
ll k;
const ll mod=1e9+7;
struct Matrix{
    int n;
    ll num[105][105];
    Matrix operator *(const Matrix &b)const{
        Matrix res=b;
        for(int i=1; i<=n; i++)
            for(int j=1; j<=n; j++){
                res.num[i][j] = 0;
                for(int k=1; k<=n; k++)
                    res.num[i][j] = (res.num[i][j]+num[i][k]*b.num[k][j]%mod)%mod;
            }
        return res;
    }
    Matrix operator ^(ll k)const{
        Matrix res;
        Matrix x = *this;
        res.n = n;
        for(int i=1; i<=n; i++)
            for(int j=1; j<=n; j++)
                if(i==j)    res.num[i][j] = 1;
                else        res.num[i][j] = 0;//搞成一个单位矩阵，单位矩阵乘矩阵A等于矩阵A本身。
        while(k){
            if(k&1) res = res * x;
            x = x * x;
            k >>= 1;
        }
        return res;
    }
}a;
int main(){
    cin>>a.n>>k;
    for(int i=1; i<=a.n; i++)
        for(int j=1; j<=a.n; j++)
            scanf("%lld", &a.num[i][j]);
    a = a ^ k;
    for(int i=1; i<=a.n; i++){
        for(int j=1; j<=a.n; j++)
            printf("%lld ", a.num[i][j]);
        printf("\n");
    }
    return 0;
}