Staircase.js

'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');

let inputString = '';
let currentLine = 0;

process.stdin.on('data', function(inputStdin) {
    inputString += inputStdin;
});

process.stdin.on('end', function() {
    inputString = inputString.split('\n');

    main();
});

function readLine() {
    return inputString[currentLine++];
}

/*
 * Complete the 'staircase' function below.
 *
 * The function accepts INTEGER n as parameter.
 */

function staircase(n) {
    // Write your code here
    var s='';
    for(var i=1;i<=n;i++){
        s='';
        for(var j=1;j<=n-i;j++){
             s=s+' ';
        }
        for(var k=i;k>0;k--){
           s=s+'#'; 
        }
        console.log(s);
    }

}

function main() {
    const n = parseInt(readLine().trim(), 10);

    staircase(n);
}