strings.swift

func twoStrings(stringA: String, stringB: String) -> String {
    
    let firstSet = Set(stringA.lowercaseString.characters)
    let secondSet = Set(stringB.lowercaseString.characters)
    
    if firstSet.intersect(secondSet).count > 0 {
        return "YES"   
    } else {
   
        return "NO"
        
    }   
}
let test = Int(readLine()!)
for var i = 0; i < test; i+=1 {
    let string1 = String(readLine()!)
    let string2 = String(readLine()!)
    print(twoStrings(string1, stringB: string2))
}