[프로그래머스] 같은 숫자는 싫어 : https://programmers.co.kr/learn/courses/30/lessons/12906
function solution(arr)
{
var answer = [];
let i = 0;
let j = 1;
while(i < arr.length) {
if (arr[i] === arr[j]) j++;
else {
answer.push(arr[i]);
i = j;
j++;
}
}
return answer;
}