get-row-col.swift

get-row-col.swift

func rowAndCol(s: Int, N: Int) -> (Int, Int) {
    var s = s - 1
    var row = N - (s / N) - 1
    var col = row % 2 != N % 2 ? s % N : N - 1 - (s % N)
    return (row, col)
}

let range = 0..<N
for row in range.reversed() {
    let reversed: [Int] = range.reversed()
    for j in range {
        let col = row % 2 == 0 ? reversed[j] : j
        print(board[row][col], terminator: " ")
    }
    print()
}


/*
from this, N*N
s = board[i][j]
var board = [
    [36, 35, 34, 33, 32, 31],
    [25, 26, 27, 28, 29, 30],
    [24, 23, 22, 21, 20, 19],
    [13, 14, 15, 16, 17, 18],
    [12, 11, 10, 9, 8, 7],
    [1, 2, 3, 4, 5, 6]
]
*/