2138.js

/** ------------------------------------------------------------------------------
 * 
 * 2138. Divide a String Into Groups of Size k
 * Topics: String
 * 
 * https://leetcode.com/problems/divide-a-string-into-groups-of-size-k/description/?envType=daily-question&envId=2025-06-22
 * 
 ------------------------------------------------------------------------------ */
var divideString = function (s, k, fill) {
  const res = [] // grouped string
  const n = s.length
  let curr = 0 // starting index of each group
  // split string
  while (curr < n) {
    const end = Math.min(curr + k, n)
    res.push(s.slice(curr, end))
    curr += k
  }
  // try to fill in the last group
  const last = res[res.length - 1]
  if (last.length < k) {
    res[res.length - 1] = last + fill.repeat(k - last.length)
  }
  return res
}

console.log()