2439번 - 별 찍기 - 2

방법 1. String(repeat: )

import Foundation

// https://www.acmicpc.net/problem/2439

let N = Int(readLine()!)!

for i in 1...N {
    print(String(repeating: " ", count: N - i), terminator: "")
    print(String(repeating: "*", count: i))
}

방법 2. 이중반복문

import Foundation

// https://www.acmicpc.net/problem/2439

let N = Int(readLine()!)!

for i in 1...N {
    var toPrint = ""
    for _ in stride(from: N - i, to: 0, by: -1) {
        toPrint += " "
    }
    for _ in 0..<i {
        toPrint += "*"
    }
    print(toPrint)
}