2434.js

/** ------------------------------------------------------------------------------
 * 
 * 2434. Using a Robot to Print the Lexicographically Smallest String
 * Topics: Hash Table, Greedy
 * https://leetcode.com/problems/using-a-robot-to-print-the-lexicographically-smallest-string/description/?envType=daily-question&envId=2025-06-06
 * 
 ------------------------------------------------------------------------------ */
/**
 * @param {string} s
 * @return {string}
 */
var robotWithString = function (s) {
  const charCount = Array(26).fill(0)
  for (const char of s) {
    charCount[char.charCodeAt(0) - 97]++
  }

  const stack = []
  let minCharIndex = 0
  let result = ""

  for (const char of s) {
    stack.push(char)
    charCount[char.charCodeAt(0) - 97]--

    while (minCharIndex < 26 && charCount[minCharIndex] === 0) {
      minCharIndex++
    }

    while (stack.length && (minCharIndex === 26 || stack[stack.length - 1].charCodeAt(0) - 97 <= minCharIndex)) {
      result += stack.pop()
    }
  }

  while (stack.length) {
    result += stack.pop()
  }

  return result
}

console.log()