Add tasks for all the new languages

Task/Sudoku/Swift/sudoku.swift

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+import Foundation
+
+typealias SodukuPuzzle = [[Int]]
+
+class Soduku {
+    let mBoardSize:Int!
+    let mBoxSize:Int!
+    var mBoard:SodukuPuzzle!
+    var mRowSubset:[[Bool]]!
+    var mColSubset:[[Bool]]!
+    var mBoxSubset:[[Bool]]!
+
+    init(board:SodukuPuzzle) {
+        mBoard = board
+        mBoardSize = board.count
+        mBoxSize = Int(sqrt(Double(mBoardSize)))
+        mRowSubset = [[Bool]](count: mBoardSize, repeatedValue: [Bool](count: mBoardSize, repeatedValue: false))
+        mColSubset = [[Bool]](count: mBoardSize, repeatedValue: [Bool](count: mBoardSize, repeatedValue: false))
+        mBoxSubset = [[Bool]](count: mBoardSize, repeatedValue: [Bool](count: mBoardSize, repeatedValue: false))
+        initSubsets()
+    }
+
+    func computeBoxNo(i:Int, _ j:Int) -> Int {
+        let boxRow = i / mBoxSize
+        let boxCol = j / mBoxSize
+
+        return boxRow * mBoxSize + boxCol
+    }
+
+    func initSubsets() {
+        for i in 0..<mBoard.count {
+            for j in 0..<mBoard.count {
+                let value = mBoard[i][j]
+
+                if value != 0 {
+                    setSubsetValue(i, j, value, true);
+                }
+            }
+        }
+    }
+
+    func isValid(i:Int, _ j:Int, var _ val:Int) -> Bool {
+        val--
+        let isPresent = mRowSubset[i][val] || mColSubset[j][val] || mBoxSubset[computeBoxNo(i, j)][val]
+        return !isPresent
+    }
+
+    func printBoard() {
+        for i in 0..<mBoardSize {
+            if i % mBoxSize == 0 {
+                println(" -----------------------")
+            }
+
+            for j in 0..<mBoardSize {
+                if j % mBoxSize == 0 {
+                    print("| ")
+                }
+
+                print(mBoard[i][j] != 0 ? String(mBoard[i][j]) : " ")
+                print(" ")
+            }
+
+            println("|")
+        }
+
+        println(" -----------------------")
+    }
+
+    func setSubsetValue(i:Int, _ j:Int, _ value:Int, _ present:Bool) {
+        mRowSubset[i][value - 1] = present
+        mColSubset[j][value - 1] = present
+        mBoxSubset[computeBoxNo(i, j)][value - 1] = present
+    }
+
+    func solve() {
+        solve(0, 0)
+    }
+
+    func solve(var i:Int, var _ j:Int) -> Bool {
+        if i == mBoardSize {
+            i = 0
+            j++
+            if j == mBoardSize {
+                return true
+            }
+        }
+
+        if mBoard[i][j] != 0 {
+            return solve(i + 1, j)
+        }
+
+        for value in 1...mBoardSize {
+            if isValid(i, j, value) {
+                mBoard[i][j] = value
+                setSubsetValue(i, j, value, true)
+
+                if solve(i + 1, j) {
+                    return true
+                }
+
+                setSubsetValue(i, j, value, false)
+            }
+        }
+
+        mBoard[i][j] = 0
+        return false
+    }
+}
+
+let board = [
+    [4, 0, 0, 0, 0, 0, 0, 6, 0],
+    [5, 0, 0, 0, 8, 0, 9, 0, 0],
+    [3, 0, 0, 0, 0, 1, 0, 0, 0],
+
+    [0, 2, 0, 7, 0, 0, 0, 0, 1],
+    [0, 9, 0, 0, 0, 0, 0, 4, 0],
+    [8, 0, 0, 0, 0, 3, 0, 5, 0],
+    [0, 0, 0, 2, 0, 0, 0, 0, 7],
+    [0, 0, 6, 0, 5, 0, 0, 0, 8],
+    [0, 1, 0, 0, 0, 0, 0, 0, 6]
+]
+
+let puzzle = Soduku(board: board)
+puzzle.solve()
+puzzle.printBoard()