[프로그래머스] 행렬의 곱셈

class Solution {
    public int[][] solution(int[][] arr1, int[][] arr2) {
        int len1 = arr1.length;
        int len2 = arr1[0].length;
        int len3 = arr2[0].length;
        int[][] answer = new int[len1][len3];
        
        for(int i=0; i<len1; i++) {
            for(int j=0; j<len2; j++) {
                for(int k=0; k<len3; k++) {
                    answer[i][k] += arr1[i][j] * arr2[j][k];
                }
            }
        }
        return answer;
    }
}