ALGORITHM/PROGRAMMERS

[프로그래머스] 행렬의 곱셈

0298 2021. 7. 30. 22:18

https://programmers.co.kr/learn/courses/30/lessons/12949#

 

코딩테스트 연습 - 행렬의 곱셈

[[2, 3, 2], [4, 2, 4], [3, 1, 4]] [[5, 4, 3], [2, 4, 1], [3, 1, 1]] [[22, 22, 11], [36, 28, 18], [29, 20, 14]]

programmers.co.kr

2021-07-30


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

#문제풀이

행렬의 곱셈

  A      B           =     AB

(i x j) (j x k)        (i x k)