duplicate encoder
const duplicateEncode = word => {
let newString = ''
word = word.toLowerCase() || word
word.split('').filter((x, index) => {
if(word.indexOf(x) !== index){
newString += ')'
}else if(word.lastIndexOf(x) !== index){
newString += ')'
}else{
newString += '('
}
})
return newString
}
console.log(duplicateEncode("O!!!!@k!!!H!!!)!!n!"))