Powerful Integers

powerful_integers.swift

class Solution {
    func powerfulIntegers(_ x: Int, _ y: Int, _ bound: Int) -> [Int] {
        guard bound >= 2 else{
            return []
        }
        
        var set = Set<Int>()
        var powerX = 1
        for i in 1..<bound where powerX <= bound{
            var powerY = 1
            while powerX + powerY <= bound {
                set.insert(powerX + powerY)
                powerY *= y
                
                if y == 1 {
                    break
                }
            }
                if x == 1 {
                    break
                }
            powerX *= x
        }
        
        return Array(set)
    }
}