Array Intersection: Find the intersection of a given set of 3 sorted arrays

IntegerArrayIntersection.swift

/// Array Intersection: Find the intersection of a given set of 3 sorted arrays
///
/// - Parameters:
///   - arrayOne: the first sorted array of Integers
///   - arrayTwo: the second sorted array of Integers
///   - arrayThree: the third sorted array of Integers
/// - Returns: an array of intersection points within the given 3 arrays
func findIntersection(arrayOne: [Int], arrayTwo: [Int], arrayThree: [Int]) -> [Int] {
  
    var results: [Int] = []
    
    var x = 0
    var y = 0
    var z = 0
    
    var oob: Bool {
        return (x >= arrayOne.count || y >= arrayTwo.count || z >= arrayThree.count)
    }
    
    while !oob {
        if arrayOne[x] == arrayTwo[y] && arrayTwo[y] == arrayThree[z] {
            results.append(arrayOne[x])
            x += 1
            y += 1
            z += 1
        } else if arrayOne[x] < arrayTwo[y] {
            x += 1
        } else if arrayTwo[y] < arrayThree[z] {
            y += 1
        } else {
            z += 1
        }
    }
    
    return results
    
}


let arrayOne = [2, 6, 9, 11, 13, 49]
let arrayTwo = [3, 6, 7, 10, 13, 18]
let arrayThree = [4, 5, 6, 9, 11, 13]


let intersect = findIntersection(arrayOne: arrayOne, arrayTwo: arrayTwo, arrayThree: arrayThree)

print(intersect)