https://programmers.co.kr/learn/courses/30/lessons/42747
function solution(citations) {
let answer = 0;
citations.sort((a,b)=>{
return a-b; // 오름차순 정렬
});
console.log(citations);
for(let i=0; i<citations.length; i++){
if(citations[i] >= citations.length-i)
return citations.length - i;
}
return answer;
}