[프로그래머스]행렬의 덧셈

func solution(_ arr1:[[Int]], _ arr2:[[Int]]) -> [[Int]] {
    let n = arr1.count
    let m = arr1[0].count

    var result = [[Int]]()

    for i in 0..<n {
        result.append([])
        for j in 0..<m {
            result[i].append(arr1[i][j] + arr2[i][j])
        }
    }

    return result
}

func solution(_ arr1:[[Int]], _ arr2:[[Int]]) -> [[Int]] {
    var arr3:[[Int]] = Array(repeating:Array(repeating:0, count:arr1[0].count), count:arr1.count)
    for i in 0..<arr1.count {
        for j in 0..<arr1[i].count {
            arr3[i][j] = arr1[i][j] + arr2[i][j]
        }
    }
    return arr3
}

Array(repeating:, count:) 사용해서 전부 0인 배열 만들어준다.

import Foundation

func solution(_ arr1:[[Int]], _ arr2:[[Int]]) -> [[Int]] {
    return zip(arr1, arr2).map{zip($0,$1).map{$0+$1}}
}