1663-smallest-string-with-a-given-numeric-value.js

/**
 * 1663. Smallest String With A Given Numeric Value
 * https://leetcode.com/problems/smallest-string-with-a-given-numeric-value/
 * Difficulty: Medium
 *
 * The numeric value of a lowercase character is defined as its position (1-indexed) in the
 * alphabet, so the numeric value of a is 1, the numeric value of b is 2, the numeric value
 * of c is 3, and so on.
 *
 * The numeric value of a string consisting of lowercase characters is defined as the sum of
 * its characters' numeric values. For example, the numeric value of the string "abe" is equal
 * to 1 + 2 + 5 = 8.
 *
 * You are given two integers n and k. Return the lexicographically smallest string with length
 * equal to n and numeric value equal to k.
 *
 * Note that a string x is lexicographically smaller than string y if x comes before y in
 * dictionary order, that is, either x is a prefix of y, or if i is the first position
 * such that x[i] != y[i], then x[i] comes before y[i] in alphabetic order.
 */

/**
 * @param {number} n
 * @param {number} k
 * @return {string}
 */
var getSmallestString = function(n, k) {
  const result = new Array(n).fill('a');
  let remainingValue = k - n;

  for (let i = n - 1; i >= 0 && remainingValue > 0; i--) {
    const addValue = Math.min(25, remainingValue);
    result[i] = String.fromCharCode(97 + addValue);
    remainingValue -= addValue;
  }

  return result.join('');
};