Insertion Sort (NSArray category)

Insertion Sort

- (NSArray *)insertionSort {
    
    //Do nothing if the array has less than or only 1 object
    if ([self count] <= 1) {
        return self;
    }
    
    NSMutableArray *sortedArray = [self mutableCopy];
    
    for (int j = 1; j < [sortedArray count]; j++) {
        
        NSNumber *key = sortedArray[j];
        
        int i = j - 1;
        
        //A[i] > key
        while (i >= 0 && [sortedArray[i] compare:key] == NSOrderedDescending) {
            sortedArray[i+1] = sortedArray[i];
            i--;
        }
        sortedArray[i+1] = key;
    }
    
    return [sortedArray copy];
}