1945. Sum of Digits of String After Convert

QUESTION:

You are given a string s consisting of lowercase English letters, and an integer k.

First, convert s into an integer by replacing each letter with its position in the alphabet (i.e., replace ‘a’ with 1, ‘b’ with 2, …, ‘z’ with 26). Then, transform the integer by replacing it with the sum of its digits. Repeat the transform operation k times in total.

For example, if s = “zbax” and k = 2, then the resulting integer would be 8 by the following operations:

Convert: “zbax” ➝ “(26)(2)(1)(24)” ➝ “262124” ➝ 262124 Transform #1: 262124 ➝ 2 + 6 + 2 + 1 + 2 + 4 ➝ 17 Transform #2: 17 ➝ 1 + 7 ➝ 8 Return the resulting integer after performing the operations described above.

Example 1:

Input: s = "iiii", k = 1
Output: 36
Explanation: The operations are as follows:
- Convert: "iiii" ➝ "(9)(9)(9)(9)" ➝ "9999" ➝ 9999
- Transform #1: 9999 ➝ 9 + 9 + 9 + 9 ➝ 36
Thus the resulting integer is 36.

Example 2:

Input: s = "leetcode", k = 2
Output: 6
Explanation: The operations are as follows:
- Convert: "leetcode" ➝ "(12)(5)(5)(20)(3)(15)(4)(5)" ➝ "12552031545" ➝ 12552031545
- Transform #1: 12552031545 ➝ 1 + 2 + 5 + 5 + 2 + 0 + 3 + 1 + 5 + 4 + 5 ➝ 33
- Transform #2: 33 ➝ 3 + 3 ➝ 6
Thus the resulting integer is 6.

Example 3:

Input: s = "zbax", k = 2
Output: 8

Constraints:

1 <= s.length <= 100
1 <= k <= 10
s consists of lowercase English letters.

EXPLANATION:

只要模拟出当前过程即可.

SOLUTION:

class Solution {
    func getLucky(_ s: String, _ k: Int) -> Int {
        var str: String = ""
        for ch in s {
            str += String(ch.asciiValue! - 96)
        }
        var result:Int = 0
        for _ in 0..<k {
            for ch in str {
                result += Int(String(ch))!
            }
            str = String(result)
            result = 0
        }
        return Int(str)!
    }
}
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