Add Border

Given a rectangular matrix of characters, add a border of asterisks(*) to it.

Example

• For

  picture = [
      "abc",
      "ded"
  ]

  the output should be

  add_border(picture) = [
      "*****",
      "*abc*",
      "*ded*",
      "*****"
  ]

Solution

PYTHON

# Version 1:
def add_border_v1(picture):
    length = len(picture)
    width = len(picture[0])
    frame = [['*'] * (width + 2) for _ in range(length + 2)]
    new_picture = []

    for i in range(length):
        for j in range(width):
            frame[i + 1][j + 1] = picture[i][j]

    for i in range(length + 2):
        new_picture.append(''.join(frame[i]))

    return new_picture


# Version 2:
def add_border_v2(picture):
    frame = '*' * (len(picture[0]) + 2)
    for i in range(len(picture)):
        picture[i] = '*' + picture[i] + '*'
    return [frame] + picture + [frame]


print(add_border_v1(["abc", "ded"]))

JAVASCRIPT

function addBorder(picture) {
  const wall = '*'.repeat(picture[0].length + 2);
  const result = [wall];
  for (let i = 0; i < picture.length; i++) {
    result.push('*' + picture[i] + '*');
  }
  result.push(wall);
  return result;
}

console.log(addBorder(['abc', 'ded']));