809. Expressive Words

func expressiveWords(_ S: String, _ words: [String]) -> Int {
        let target = encode(S)
        var count = 0
        for w in words{
            if canStrich(encode(w), target) {
                count += 1
            }
        }
        return count
    }

    func encode(_ str: String) -> [(Character, Int)] {
        var res = [(Character, Int)] ()
        var preChar : Character?
        var count = 1
        for c in str {
            if preChar == nil {
                preChar = c
                continue
            }
            if preChar != nil && c == preChar{
                count += 1
            }else{
                res.append((preChar!, count))
                preChar = c
                count = 1
            }
        }
        res.append((preChar!, count))
        return res
    }


    func canStrich(_ str : [(Character, Int)], _ target : [(Character, Int)]) -> Bool{
        if str.count != target.count { return false}
        var i = 0
        // print(str)
        while i < str.count{
            let p1 = str[i]
            let p2 = target[i]
            if p1.0 != p2.0 { return false}
            if p1.1 != p2.1 {
                if p2.1 <= 2 || p2.1 < p1.1{ return false }
            }
            i += 1
        }
        return true
    }