Question

How to find the sum of each row and each column of a matrix (2D array) in Swift

Answer 1

import Foundation

let arr: [[Int]] = [
    [1, 2, 3, 5],
    [4, 5, 6, 5],
    [7, 8, 9, 5]
]

let rows = arr.count
let cols = arr[0].count

var sumRow: Int
for i in 0..<rows {
    sumRow = 0
    for j in 0..<cols {
        sumRow += arr[i][j]
    }
    print("Sum of row: \(i) = \(sumRow)")
}

var sumCol: Int
for i in 0..<cols {
    sumCol = 0
    for j in 0..<rows {
        sumCol += arr[j][i]
    }
    print("Sum of col: \(i) = \(sumCol)")
}



/*
run:
  
Sum of row: 0 = 11
Sum of row: 1 = 20
Sum of row: 2 = 29
Sum of col: 0 = 12
Sum of col: 1 = 15
Sum of col: 2 = 18
Sum of col: 3 = 15
  
*/

 

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