func dictSignature(s : String) -> Dictionary<String, Int> {
    var chars = Dictionary<String, Int>();
    for y in s {
        var x = String(y)
        if let v = chars[x] {
            chars.updateValue(v + 1, forKey: x)
            chars[x] = v + 1;
        } else {
            chars[x] = 1;
        }
    }
    return chars;
}

func isAnagram(s1: String, s2: String) -> Bool {
    let (d1, d2) = (dictSignature(s1), dictSignature(s2));
    return d1 == d2;
}

let y = isAnagram("testing", "one two three");
let x = isAnagram("testing", "gnitset");