https://school.programmers.co.kr/learn/courses/30/lessons/12950
배열크기 할당에 주의
class Solution {
public int[][] solution(int[][] arr1, int[][] arr2) {
int[][] answer = new int[arr1.length][arr1[1].length];
for(int i =0; i < arr1.length; i++){
for (int j=0; j <arr1[1].length; j++){
answer[i][j]=arr1[i][j]+arr2[i][j];
}
}
return answer;
}
}