
word 순회function countVowelSubstrings(word: string): number {
let count = 0
const vowels = new Set('aeiou')
for(let i = 0; i < word.length; i ++) {
if(!vowels.has(word[i])) continue
const curStr = new Set(word[i])
for(let j = i + 1; j < word.length; j++) {
if(!vowels.has(word[j])) break
curStr.add(word[j])
if(curStr.size === vowels.size) count++
}
}
return count
};