Add tasks for all the new languages

Task/Maze-generation/Swift/maze-generation.swift

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+import Foundation
+
+class Direction {
+    var vect:(Int, Int, Int)
+    var bit:Int {
+        let (bit, dx, dy) = vect
+        return bit
+    }
+
+    var dx:Int {
+        let (bit, dx, dy) = vect
+        return dx
+    }
+
+    var dy:Int {
+        let (bit, dx, dy) = vect
+        return dy
+    }
+
+    var opposite:Direction {
+        switch (vect) {
+        case (1, 0, -1):
+            return Direction(bit: 2, dx: 0, dy: 1)
+        case (2, 0, 1):
+            return Direction(bit: 1, dx: 0, dy: -1)
+        case (4, 1, 0):
+            return Direction(bit: 8, dx: -1, dy: 0)
+        case (8, -1, 0):
+            return Direction(bit: 4, dx: 1, dy: 0)
+        default:
+            return Direction(bit: 0, dx: 0, dy: 0)
+        }
+    }
+
+    init(bit:Int, dx:Int, dy:Int) {
+        self.vect = (bit, dx, dy)
+    }
+}
+
+let N = Direction(bit: 1, dx: 0, dy: -1)
+let S = Direction(bit: 2, dx: 0, dy: 1)
+let E = Direction(bit: 4, dx: 1, dy: 0)
+let W = Direction(bit: 8, dx: -1, dy: 0)
+
+class MazeGenerator {
+    let x:Int!
+    let y:Int!
+    var maze:[[Int]]!
+
+    init(_ x:Int, _ y:Int) {
+        self.x  = x
+        self.y = y
+        var col = [Int](count: y, repeatedValue: 0)
+        self.maze = [[Int]](count: x, repeatedValue: col)
+        generateMaze(0, 0)
+    }
+
+    func display() {
+        for i in 0..<y {
+            // Draw top edge
+            for j in 0..<x {
+                print((maze[j][i] & 1) == 0 ? "+---" : "+   ")
+            }
+            println("+")
+
+            // Draw left edge
+            for j in 0..<x {
+                print((maze[j][i] & 8) == 0 ? "|   " : "    ")
+            }
+            println("|")
+        }
+
+        // Draw bottom edge
+        for j in 0..<x {
+            print("+---")
+        }
+        println("+")
+    }
+
+    func generateMaze(cx:Int, _ cy:Int) {
+        var dirs = [N, S, E, W] as NSMutableArray
+        for i in 0..<dirs.count {
+            let x1 = Int(arc4random()) % dirs.count
+            let x2 = Int(arc4random()) % dirs.count
+            dirs.exchangeObjectAtIndex(x1, withObjectAtIndex: x2)
+        }
+
+        for dir in dirs {
+            var dir = dir as Direction
+            let nx = cx + dir.dx
+            let ny = cy + dir.dy
+            if (between(nx, self.x) && between(ny, self.y) && (maze[nx][ny] == 0)) {
+                    maze[cx][cy] |= dir.bit
+                    maze[nx][ny] |= dir.opposite.bit
+                    generateMaze(nx, ny)
+            }
+
+        }
+    }
+
+    func between(v:Int, _ upper:Int) -> Bool {
+        return (v >= 0) && (v < upper)
+    }
+}
+
+let x = 10
+let y = 10
+let maze = MazeGenerator(x, y)
+maze.display()