https://www.hackerrank.com/challenges/staircase/problem?h_r=next-challenge&h_v=zen

hackerrank--staircase.js

function parse_frame_by_size (size, i) {
    const spaces_to_add = size - i
    const bricks_to_add = i
    
    let frame = ""
    for (let n = 1; n <= spaces_to_add; n++) {
        frame = frame + " "
    }
    for (let n = 1; n <= bricks_to_add; n++) {
        frame = frame + "#"
    }

    return frame + `\n`
}

function mount_staircase(size = 8) {
    let screen = ""
    for (let i = 1; i <= size; i++ ) {
        const frame = parse_frame_by_size(size, i)
        screen = screen + frame
    }
    return screen
}

console.log( mount_staircase() )