33. 행렬의 덧셈

문제 설명

두 행렬의 element wise addition을 한 결과를 리턴.

Inputs

Variable Name	type	meaning
arr1	Vector[Vector[Int]]	matrix 1
arr2	Vector[Vector[Int]]	matrix 2

output

return Vector[Vector[Int]] // element-wise added.

Conditions

• arr1 arr2
  • row and column length < 500

Test cases

arr1	arr2	return
[[1,2],[2,3]]	[[3,4],[5,6]]	[[4,6],[7,9]]
[[1],[2]]	[[3],[4]]	[[4],[6]]

Solution

두 행렬 zip후 map → 각 row별로 zip 후 map → element1+ element2

def solution(arr1: Vector[Vector[Int]], arr2: Vector[Vector[Int]]): Vector[Vector[Int]] = {
  arr1.zip(arr2).map(row => 
                     row._1.zip(row._2).map(cell => 
                                            cell._1+cell._2)
                    )
}

Study from Implementation