marioeguiluz

//Safe bounds check for Array
//http://stackoverflow.com/questions/25329186/safe-bounds-checked-array-lookup-in-swift-through-optional-bindings
extension Collection {
    /// Returns the element at the specified index iff it is within bounds, otherwise nil.
    subscript (safe index: Index) -> Iterator.Element? {
        return index >= startIndex && index < endIndex ? self[index] : nil
    }
}

//Helper function to exchange position in one array

marioeguiluz

////////////////HEAP SORT////////////////
int leftLeafIndex(int rootIndex){
    int heapIndex = rootIndex+1;
    return heapIndex*2-1;
}

int rightLeafIndex(int rootIndex){
    int heapIndex = rootIndex+1;
    return heapIndex*2+1-1;
}

marioeguiluz

//Merge Sort
func mergeSort<T:Comparable>(_ unsortedArray:Array<T>)->Array<T>{
    var unsortedArray = unsortedArray
    if unsortedArray.count < 2 {
        return unsortedArray
    }
    
    let pivot:Int = unsortedArray.count/2
    let leftArray:Array<T> = Array(unsortedArray[0..<pivot])
    let rightArray:Array<T> = Array(unsortedArray[pivot..<unsortedArray.count])

marioeguiluz

////////////////MERGE SORT////////////////
NSArray* mergeArrays(NSArray* A, NSArray* B) {
    NSMutableArray *orderedArray = [NSMutableArray new];
    long indexLeft = 0;
    long indexRight = 0;
    
    while (indexLeft < [A count] && indexRight < [B count]) {
        if ([A[indexLeft] intValue] < [B[indexRight]intValue]) {
            [orderedArray addObject:A[indexLeft++]];
        }else if ([A[indexLeft] intValue] > [B[indexRight]intValue]){

marioeguiluz

//Helper function to exchange position in one array
//From: http://stackoverflow.com/questions/24077880/swift-make-method-parameter-mutable
func exchange<T>(_ data: inout [T], i:Int, j:Int) {
    let temp:T = data[i]
    data[i] = data[j]
    data[j] = temp
}

//Insertion Sort of an array of integers
func insertionSort<T:Comparable>(_ unsortedArray:Array<T>)->Array<T>{

marioeguiluz

//Insertion Sort of an array of integers
//**************************************
NSMutableArray* insertionSort(NSMutableArray* unsortedArray){
    if(!unsortedArray) return nil;
    if(unsortedArray.count<2) return unsortedArray;
    
    for (int j=1; j<unsortedArray.count; j++) {
        int i = j;
        while(i>0 && [[unsortedArray objectAtIndex:(i-1)] intValue] > [[unsortedArray objectAtIndex:i] intValue])
        {