solution.ts

/*
 * @lc app=leetcode id=744 lang=javascript
 *
 * [744] Find Smallest Letter Greater Than Target
 */

import { LowerLetter } from '../../helper/types';

// @lc code=start

type Char = LowerLetter;

/**
 * @param {character[]} letters
 * @param {character} target
 * @return {character}
 */
const nextGreatestLetter = (letters: Char[], target: Char): Char => {
  // * ['60 ms', '82.59 %', '36.2 MB', '100 %']

  let left = 0;
  let right = letters.length - 1;

  while (left < right) {
    const mid = ~~((left + right) / 2);
    const c = letters[mid];
    if (c <= target) {
      left = mid + 1;
    } else {
      right = mid;
    }
  }

  return left === right && letters[left] > target ? letters[left] : letters[0];
};
// @lc code=end

export { nextGreatestLetter };