Find and Replace

find_and_replace.swift

class Solution {
    func findAndReplacePattern(_ words: [String], _ pattern: String) -> [String] {
        var output = [String]()
        for word in words {
           if isMatch(word,pattern) {
               output.append(word)
           }
        }
        return output
    }
    
    func isMatch(_ word:String, _ pattern:String) -> Bool {
        var mapW = [Character:Character]()
        var mapP = [Character:Character]()
        
        for (w,p) in zip(word,pattern){
            if mapW[w] == nil{
                mapW[w] = p
            }
            
            if mapP[p] == nil{
                mapP[p] = w
            }
           
            if mapW[w] != p || mapP[p] != w {
                return false
            }
        }
        
        return true
    }
}