프로그래머스 - 행렬의 곱셈

class Solution {
    public int[][] solution(int[][] arr1, int[][] arr2) {
        int first = arr1.length;
        int second = arr2[0].length;
        int[][] answer = new int[first][second];
        
        for (int i=0; i<arr1.length; i++) {
            for (int j=0; j<arr2[0].length; j++) {
                for(int k=0; k<arr1[0].length; k++){
                    answer[i][j] += arr1[i][k] * arr2[k][j];    
                }
                
            }
        }
        
        return answer;
    }
}