Directions: Write a function that accepts a positive number N. The function should console.log() a pyramid shape with N levels using the "#" character. Make sure the pyramid has spaces on both the left and right hand sides.

Examples:

pyramid(1)
;('#')
pyramid(2)
;(' # ')
;('###')
pyramid(3)
;('  #  ')
;(' ### ')
;('#####')

Iterative Solution

Calculate the midpoint of the number of columns. Get the index here.
Need to determine relationship between the number of rows and the number of columns. Can be done with n * 2 - 1.
Need to create a range where we want to add # characters.

const column = [0, 1, 2, 3, 4]
const row = 0
// need to produce a '#' at index 2 from row of 0

const column = [0, 1, 2, 3, 4]
const row = 1
// need to produce a '#' at index 1,2,3 from row of 1, and spaces at index 0, 4

If you determine the midpoint (center index), you can take the 'row' number and add it to the midpoint on either side.

function pyramid(n) {
  const midpoint = Math.floor((2 * n - 1) / 2) // midpoint of our row

  for (let row = 0; row < n; row++) {
    let level = ''
    // need to determine correct number of columns
    for (let col = 0; col < n * 2 - 1; col++) {
      // if we are in the middle of the row, add a '#'
      // add a space to the left and right, depending on the row we are on.
      if (midpoint - row <= col && midpoint + row >= col) {
        level += '#'
      } else {
        level += ' '
      }
    }
    console.log(level)
  }
}
pyramid(4)

Recursive Solution

function pyramid(n, row = 0, level = '') {
  if (row === n) {
    return
  }

  // when we reach the end of a level.
  // max number of columns is  2 * n - 1
  if (level.length === 2 * n - 1) {
    console.log(level)
    return pyramid(n, row + 1)
  }

  // get midpoint index
  const midpoint = Math.floor((2 * n - 1) / 2)

  // contains the character we are adding to our level string
  let add

  // if looking at the right and left side of the midpoint
  // we determine which column we are on by looking at the level string length
  if (midpoint - row <= level.length && midpoint + row >= level.length) {
    add = '#'
  } else {
    add = ' '
  }

  pyramid(n, row, level + add)
}