Still working on it, a little confused

ArraysAndListHW.playground/Contents.swift

@@ -0,0 +1,158 @@
+//: Playground - noun: a place where people can play
+
+import Cocoa
+
+//1.
+var sudokuBoard = [
+    [5, 0, 8, 0, 7, 3, 1, 9, 0],
+    [9, 0, 0, 6, 0, 0, 4, 0, 8],
+    [0, 0, 0, 9, 0, 8, 0, 3, 5],
+    [0, 7, 0, 0, 0, 0, 0, 6, 0],
+    [0, 0, 2, 0, 0, 0, 9, 0, 0],
+    [0, 1, 0, 0, 0, 0, 0, 8, 0],
+    [1, 9, 0, 3, 0, 6, 0, 0, 0],
+    [2, 0, 3, 0, 0, 7, 0, 0, 9],
+    [0, 8, 7, 1, 9, 0, 3, 0, 4]]
+
+func getValidOutputs(arr:[[Int]], r:Int, c:Int) -> [Int] {
+    //checking row
+    var validNumbers = Array(count: 10, repeatedValue: true)
+    for i in 0..<sudokuBoard.count {
+        let numberToBeMarked = sudokuBoard[r][i]
+       validNumbers[numberToBeMarked] = false
+
+    }
+
+
+
+    //checking column
+    for i in 0..<sudokuBoard.count {
+        let numberToBeMarked = sudokuBoard[i][c]
+        validNumbers[numberToBeMarked] = false
+    }
+
+    //checking 3 x 3 
+
+    return [Int]()
+}
+
+getValidOutputs(sudokuBoard, r: 0, c: 1)
+//check to see if the number is equal to any number in the row
+//check to see if the number is equal to any number in the column
+//check to see if the number is equal to any in the 3 * 3
+//if no matches, print the number
+
+//2. 
+var sampleInput =
+[[1,2,3,4],
+ [5,6,7,8],
+ [9,0,1,2],
+ [3,4,5,6],
+ [3,4,5,6]]
+
+func rotateNinetyDegrees(arry:[[Int]]) -> [[Int]] {
+    var matrixBoard = Array(count: sampleInput[0].count, repeatedValue: Array(count: sampleInput.count, repeatedValue: 0))
+
+    //horizontal
+    for i in 0..<sampleInput.count {
+        //vertical
+        for j in 0..<sampleInput[0].count {
+            //new matrix : matrixBoard [horizontal][vertical] =
+            //modified original matrix : sampleInput [reversed vertical -> sampleInput.count - 1 - i][revers
+            matrixBoard[j][sampleInput.count - 1 - i] = sampleInput[i][j]
+        }
+    }
+    return matrixBoard
+}
+print(rotateNinetyDegrees(sampleInput))
+
+
+//let number of rows == number of columns and number of columns == number of rows
+//output column(s) in a row(s) in reverse order
+
+
+//3.
+//var array = [4,3,2,1]
+//
+//func sort(values:[Int]) -> [Int] {
+//    let left = values[0...1]
+//    return values
+//    var left = values[0...1]
+//    if left[0] > left[1] {
+//        let t = left[0]
+//        left[0] = left[1]
+//        left[1] = t
+//    }
+//    var right = values[2...4]
+//    if right[0] > right[1] {
+//        let t = right[1]
+//        right[0] = right[1]
+//        right[1] = t
+//        print(right)
+//    }
+//}
+
+//print(sort(array))
+
+var data = [4, 3, 2, 1]
+
+func merge_sort<T: Comparable>(inout array: [T]){
+    if array.count <= 1{
+        return
+    }
+
+    // Split lists into equal sized sublists
+    var middle = array.count
+    middle /= 2
+    var left = [T]()
+    var right = [T]()
+
+    for x in 0..<middle{
+        left.append(array[x])
+    }
+
+    for y in middle..<array.count{
+        right.append(array[y])
+    }
+
+    // Recursively sort sublists
+    merge_sort(&left)
+    merge_sort(&right)
+
+    // Merge the sorted sublists
+    array = merge(&left,right: &right)
+}
+
+/*
+Merges two lists
+*/
+func merge<T: Comparable>(inout left: [T], inout right:[T])-> [T]{
+
+    var result = [T]()
+
+    // Merge taking lowest value first seen
+    while (!left.isEmpty && !right.isEmpty){
+        if left[0] <= right[0]{
+            result.append(left[0])
+            left.removeAtIndex(0)
+        }else{
+            result.append(right[0])
+            right.removeAtIndex(0)
+        }
+    }
+
+    // Handle remaining elements
+    while !left.isEmpty{
+        result.append(left[0])
+        left.removeAtIndex(0)
+    }
+    while !right.isEmpty{
+        result.append(right[0])
+        right.removeAtIndex(0)
+    }
+
+    return result
+}
+
+merge_sort(&data)
+

ArraysAndListHW.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='osx'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

ArraysAndListHW.playground/timeline.xctimeline

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Timeline
+   version = "3.0">
+   <TimelineItems>
+   </TimelineItems>
+</Timeline>