프로그래머스 | 2 x n 타일링

function solution(n) {
    var answer = 0;
    let arr=new Array(n+1).fill(0);
    arr[0]=0;
    arr[1]=1;
    arr[2]=2;
    for(let i=3;i<n+1;i++){
        arr[i]=(arr[i-1]+arr[i-2])%1000000007;
    }
    answer=arr[n]
    return answer;
}