[Programmers] 같은 숫자는 싫어

vector<int> solution(vector<int> arr)
{
    vector<int> answer;
    int size = arr.size();
    answer.push_back(arr[0]);
    
    for(int i=0; i<size-1; i++){
        if( arr[i] != arr[i+1]){
            answer.push_back(arr[i+1]);
        }
    }
    
    return answer;
}