890. Find and Replace Pattern

    func findAndReplacePattern(_ words: [String], _ pattern: String) -> [String] {
        let p = decodeStr( pattern)
        let n = pattern.count
        var res = [String]()
        for w in words{
            if w.count != n { continue}
            if decodeStr(w) == p{
                res.append(w)
            }

        }
        return res
    }

    func decodeStr(_ str: String) -> [Int]{
        var map = [Character: Int]()
        var res = [Int]()
        for char in str{
            if let index = map[char]{
                res.append(index)
            }else{
                let index = map.count
                map[char] = index
                res.append(index)
            }
        }
        return res
    }