Beginning and End Pairs [Edabit]

Edabit

Write a function that pairs the first number in an array with the last, the second number with the second to last, etc.

Examples

pairs([1, 2, 3, 4, 5, 6, 7]) ➞ [[1, 7], [2, 6], [3, 5], [4, 4]]

pairs([1, 2, 3, 4, 5, 6]) ➞ [[1, 6], [2, 5], [3, 4]]

pairs([5, 9, 8, 1, 2]) ➞ [[5, 2], [9, 1], [8, 8]]

pairs([]) ➞ []

Notes

• If the array has an odd length, repeat the middle element twice for the last pair.
• Return an empty array if the input is an empty array.

Solution:

function pairs(arr) {
  let sol = [];
  while (arr.length) {
    if (arr.length == 1) {
      let num = arr.pop();
      sol.push([num, num]);
    } else {
      sol.push([arr.shift(), arr.pop()]);
    }
  }
  return sol;
}