bbbbbbbb.js

const lenCheck = (n, str) => str.length < n ? '0'.repeat(n - str.length) + str : str;

function solution(n, arr1, arr2) {
    const answer = [];
    
    for(let i=0; i<arr1.length; i++) {
        const n1 = lenCheck(n, (+arr1[i]).toString(2));
        const n2 = lenCheck(n, (+arr2[i]).toString(2));
        
        const l = [];
        for(let j=0; j < n; j++) {
            l.push(n1[j] === '1' || n2[j] === '1' ? '#' : ' ');
        }
        
        answer[i] = l.join('');
    }
    
    return answer;
}