완주하지 못한 선수

function solution(participant, completion) {

let all=participant.sort();
let part=completion.sort();
let loser=[] ;
for(let i=0; i<all.length; i++){
    if(all[i]!=part[i]){
        loser+=all.slice(i,i+1);
        all=all.splice(i);
        return loser;
        continue;
    }
}
}