lifegame.swift

let Size : Int = 40
var cells = [Array<Bool>]()

func min(a:Int, b:Int) -> Int {
    if a > b {return b } else { return a }
}
func max(a:Int, b:Int) -> Int {
    if a > b { return a } else { return b }
}

for y in 0 ... Size {
    var xs = [Bool]()
    for x in 0 ... Size {
        var isAlive = false
        switch y {
            case 19: isAlive = x == 20
            case 20: isAlive = 19 <= x && x <= 21
            case 21: isAlive = x == 19
            default: ()
        }
        xs.append(isAlive)
    }
    cells.append(xs)
}

for _ in 0 ... 100 {
    var nexts = [Array<Bool>]()
    for y in 0 ... Size {
        var xs = [Bool]()
        for x in 0 ... Size {
            var neighbors = 0    
            for yy in max(0, y-1) ... min(y+1, Size) {
                for xx in max(0, x-1) ... min(x+1, Size) {
                    if yy != y || xx != x {
                        if cells[yy][xx] {
                            neighbors += 1
                        }
                    }
                }
            }
            var isAlive = false
            if cells[y][x] {
                isAlive = 2 <= neighbors && neighbors <= 3
            } else {
                isAlive = 3 == neighbors
            }
            xs.append(isAlive)
        }
        nexts.append(xs)
    }
    cells = nexts
}
for y in 0 ... Size {
    var line = ""
    for x in 0 ... Size {
        line += (cells[y][x] ? "*" : " ")
    }
    print(line)
}