solves sum of digits of string after convert

Author: anishLearnsToCode

README.md

@@ -467,7 +467,7 @@
 | 1933 | 🔒 [Check If String Is Decomposable Into Value EqualSubstrings](https://leetcode.com/problems/check-if-string-is-decomposable-into-value-equal-substring) |                                                                                                                                                                                      |                                                                                                                                   |
 | 1935 | [Maximum Number of Words You Can Type](https://leetcode.com/problems/maximum-number-of-words-you-can-type)                                                |                                                         [![Java](assets/java.png)](src/MaximumNumberOfWordsYouCanType.java)                                                          |                                                                                                                                   |
 | 1941 | [Check if All Characters Have Equal Number of Occurrences](https://leetcode.com/problems/check-if-all-characters-have-equal-number-of-occurrences)        |                                                [![Java](assets/java.png)](src/CheckIfAllCharactersHaveEqualNumberOfOccurrences.java)                                                 |                                                                                                                                   |
-| 1945 | [Sum of Digits of String After Convert](https://leetcode.com/problems/sum-of-digits-of-string-after-convert)                                              |                                                                                                                                                                                      |                                                                                                                                   |
+| 1945 | [Sum of Digits of String After Convert](https://leetcode.com/problems/sum-of-digits-of-string-after-convert)                                              |                                                         [![Java](assets/java.png)](src/SumOfDigitsOfStringAfterConvert.java)                                                         |                                                                                                                                   |
 | 1952 | [Three Divisors](https://leetcode.com/problems/three-divisors)                                                                                            |                                                                                                                                                                                      |                                                                                                                                   |
 | 1957 | [Delete Characters to Make Fancy String](https://leetcode.com/problems/delete-characters-to-make-fancy-string)                                            |                                                                                                                                                                                      |                                                                                                                                   |
 | 1961 | [Check If String Is a Prefix of Array](https://leetcode.com/problems/check-if-string-is-a-prefix-of-array)                                                |                                                                                                                                                                                      |                                                                                                                                   |

src/SumOfDigitsOfStringAfterConvert.java

@@ -0,0 +1,39 @@
+// https://leetcode.com/problems/sum-of-digits-of-string-after-convert
+// T: O(|s|* k)
+// S: O(|s|)
+
+public class SumOfDigitsOfStringAfterConvert {
+    public int getLucky(String s, int k) {
+        final String convertedString = convert(s);
+        int num = sumOfDigits(convertedString);
+        for (int i = 0 ; i < k - 1 ; i++) {
+            num = sumOfDigits(num);
+        }
+        return num;
+    }
+
+    private String convert(String s) {
+        final StringBuilder result = new StringBuilder();
+        for (int i = 0 ; i < s.length() ; i++) {
+            result.append(s.charAt(i) - 'a' + 1);
+        }
+        return result.toString();
+    }
+
+    private int sumOfDigits(int number) {
+        int sum = 0;
+        while (number > 0) {
+            sum += number % 10;
+            number /= 10;
+        }
+        return sum;
+    }
+
+    private int sumOfDigits(String number) {
+        int sum = 0;
+        for (int i = 0 ; i < number.length() ; i++) {
+            sum += number.charAt(i) - '0';
+        }
+        return sum;
+    }
+}