(C++) - 백준(BOJ) 10830번 : 행렬 제곱 답

문제링크 : https://www.acmicpc.net/problem/10830

#include <iostream>
using namespace std;
long long a[6][6],ans[6][6],c[6][6],n,b;
void cal(long long a[6][6], long long b[6][6])
{
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
        {
            c[i][j] = 0;
            for (int k = 1; k <= n; k++)
            {
                c[i][j] += a[i][k] * b[k][j];
            }
            c[i][j] %= 1000;
        }
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            a[i][j] = c[i][j];
    
}
int main() {
    cin >> n >> b;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
        {
            cin >> a[i][j];
 
        }
        ans[i][i] = 1;
    }
 
    while (b > 0)
    {
        if (b % 2 == 1)//지수가 홀수면
        {
            cal(ans, a);
        }
        cal(a, a);
        b /= 2;
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
            cout << ans[i][j] << ' ';
        cout << '\n';
    }
}