DAY38：Duplicate Encoder

題目連結

https://www.codewars.com/kata/54b42f9314d9229fd6000d9c

解法

function duplicateEncode(word) {
    word = word.toLowerCase()
    let result = ''
    let n = {}

    for (const char of word) {
        n[char] ? n[char]++ : n[char] = 1
    }
    for (const char of word) {
        result += n[char] > 1 ? ')' : '('
    }

    return result
}