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

/*
 * @lc app=leetcode id=1663 lang=cpp
 *
 * [1663] Smallest String With A Given Numeric Value
 *
 * https://leetcode.com/problems/smallest-string-with-a-given-numeric-value/description/
 *
 * algorithms
 * Medium (59.91%)
 * Likes:    367
 * Dislikes: 9
 * Total Accepted:    29.8K
 * Total Submissions: 46.3K
 * Testcase Example:  '3\n27'
 *
 * 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.
 * 
 * 
 * Example 1:
 * 
 * 
 * Input: n = 3, k = 27
 * Output: "aay"
 * Explanation: The numeric value of the string is 1 + 1 + 25 = 27, and it is
 * the smallest string with such a value and length equal to 3.
 * 
 * 
 * Example 2:
 * 
 * 
 * Input: n = 5, k = 73
 * Output: "aaszz"
 * 
 * 
 * 
 * Constraints:
 * 
 * 
 * 1 <= n <= 10^5
 * n <= k <= 26 * n
 * 
 * 
 */

// @lc code=start
class Solution {
public:
    string getSmallestString(int n, int k) {
        ng getSmallestString(int n, int k) {
        string res(n, 'a');
        k -= n;
        for (int i = n - 1; i >= 0; --i) {
            int val = min(25, k);
            k -= val;
            res[i] += val;
        }
        return res;
    }
};
// @lc code=end