Codefights

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Add Border

Description

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

Example

For
picture = ["abc",
"ded"]

the output should be

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

Input/Output

  • [execution time limit] 4 seconds (js)

  • [input] array.string picture

    A non-empty array of non-empty equal-length strings.

    Guaranteed constraints:
    1 ≤ picture.length ≤ 100,
    1 ≤ picture[i].length ≤ 100.

  • [output] array.string

    • The same matrix of characters, framed with a border of asterisks of width 1.

[JavaScript (ES6)] Syntax Tips

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// Prints help message to the console
// Returns a string
function helloWorld(name) {
console.log("This prints to the console when you Run Tests");
return "Hello, " + name;
}

Solution

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function addBorder(picture) {
  return [Array(picture[0].length + 2).fill('*').join('')]
    .concat(
      picture.map(r => '*' + r + '*'),
      [Array(picture[0].length + 2).fill('*').join('')]
    )
}