Alexander D.

func repeatStr0(_ n: Int, _ string: String) -> String {
            var accumulator = ""
            for _ in 0 ..< n {
                accumulator.append(string)
            }
            return accumulator
        }

        func repeatStr1(_ n: Int, _ string: String) -> String {
            var accumulator = ""
            (0 ..< n).forEach {_ in accumulator.append(string) }
            return accumulator
        }

        func repeatStr2(_ n: Int, _ string: String) -> String {
            return (0 ..< n).reduce(into: "") { s, _ in s.append(string) }
        }