Calculate all permutations of a string in Swift

Question

For the string \"ABC\" the code snippet below calculates 5 of the 6 total permutations. My strategy was to insert each character at each index possible index. B

Answer 1

A very straightforward approach as also suggested in Swift coding challenges.

 func permutation(string: String, current: String = "") {
        let length = string.characters.count
        let strArray = Array(string.characters)
        if (length == 0) {
            // there's nothing left to re-arrange; print the result
            print(current)
            print("******")
        } else {
            print(current)
            // loop through every character
            for i in 0 ..< length {
                // get the letters before me
                let left = String(strArray[0 ..< i])
                // get the letters after me
                let right = String(strArray[i+1 ..< length])
                // put those two together and carry on
                permutation(string: left + right, current: current +
                    String(strArray[i]))
            }

        }
    }