Question

How to sort each column of a matrix with strings in Swift

Answer 1

import Foundation

func sortColumns(matrix: inout [[String]]) {
    let rows = matrix.count
    let cols = matrix[0].count

    for col in 0..<cols {
        // Extract column into an array
        var column = [String]()
        for row in 0..<rows {
            column.append(matrix[row][col])
        }

        // Sort the column
        column.sort()

        // Place sorted values back into the matrix
        for row in 0..<rows {
            matrix[row][col] = column[row]
        }
    }
}

func printMatrix(_ matrix: [[String]]) {
    for row in matrix {
        print(row.joined(separator: " "))
    }
}

var matrix = [
    ["ccc", "zzzz", "yyyyyy"],
    ["eeee", "aaa", "ffff"],
    ["uu", "hhh", "uuu"],
    ["bbb", "gg", "x"]
]

print("Original Matrix:")
printMatrix(matrix)

sortColumns(matrix: &matrix)

print("\nSorted Matrix:")
printMatrix(matrix)

 
 
/*
run:
 
Original Matrix:
ccc zzzz yyyyyy
eeee aaa ffff
uu hhh uuu
bbb gg x

Sorted Matrix:
bbb aaa ffff
ccc gg uuu
eeee hhh x
uu zzzz yyyyyy

*/

 

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