Merge pull request #26 from fluttermiddlepodcast/2520_Count_the_Digits_That_Divide_a_Number

added "2520. Count the Digits That Divide a Number"

Author: fluttermiddlepodcast

README.md

@@ -4,23 +4,24 @@ Solutions from [LeetCode](https://leetcode.com) on Dart.
 
 ## Easy
 
-| Name                                    | LeetCode                                                                   | Solution                                                    |
-|-----------------------------------------|----------------------------------------------------------------------------|-------------------------------------------------------------|
-| 9. Palindrome Number                    | [Link](https://leetcode.com/problems/palindrome-number/)                   | [Link](./lib/easy/palindrome_number.dart)                   |
-| 26. Remove Duplicates from Sorted Array | [Link](https://leetcode.com/problems/remove-duplicates-from-sorted-array/) | [Link](./lib/easy/remove_duplicates_from_sorted_array.dart) |
-| 136. Single Number                      | [Link](https://leetcode.com/problems/single-number/)                       | [Link](./lib/easy/single_number.dart)                       |
-| 144. Binary Tree Preorder Traversal     | [Link](https://leetcode.com/problems/binary-tree-preorder-traversal/)      | [Link](./lib/easy/binary_tree_preorder_traversal.dart)      |
-| 169. Majority Element                   | [Link](https://leetcode.com/problems/majority-element/)                    | [Link](./lib/easy/majority_element.dart)                    |
-| 217. Contains Duplicate                 | [Link](https://leetcode.com/problems/contains-duplicate/)                  | [Link](./lib/easy/contains_duplicate.dart)                  |
-| 226. Invert Binary Tree                 | [Link](https://leetcode.com/problems/invert-binary-tree/)                  | [Link](./lib/easy/invert_binary_tree.dart)                  |
-| 342. Power of Four                      | [Link](https://leetcode.com/problems/power-of-four/)                       | [Link](./lib/easy/power_of_four.dart)                       |
-| 414. Third Maximum Number               | [Link](https://leetcode.com/problems/third-maximum-number/)                | [Link](./lib/easy/third_maximum_number.dart)                |
-| 796. Rotate String                      | [Link](https://leetcode.com/problems/rotate-string/)                       | [Link](./lib/easy/rotate_string.dart)                       |
-| 944. Delete Columns to Make Sorted      | [Link](https://leetcode.com/problems/delete-columns-to-make-sorted/)       | [Link](./lib/easy/delete_columns_to_make_sorted.dart)       |
-| 2119. A Number After a Double Reversal  | [Link](https://leetcode.com/problems/a-number-after-a-double-reversal/)    | [Link](./lib/easy/third_maximum_number.dart)                |
-| 2239. Find Closest Number to Zero       | [Link](https://leetcode.com/problems/find-closest-number-to-zero/)         | [Link](./lib/easy/find_closest_number_to_zero.dart)         |
-| 2481. Minimum Cuts to Divide a Circle   | [Link](https://leetcode.com/problems/minimum-cuts-to-divide-a-circle/)     | [Link](./lib/easy/minimum_cuts_to_divide_a_circle.dart)     |
-| 2490. Circular Sentence                 | [Link](https://leetcode.com/problems/circular-sentence/)                   | [Link](./lib/easy/circular_sentence.dart)                   |
+| Name                                        | LeetCode                                                                     | Solution                                                      |
+|---------------------------------------------|------------------------------------------------------------------------------|---------------------------------------------------------------|
+| 9. Palindrome Number                        | [Link](https://leetcode.com/problems/palindrome-number/)                     | [Link](./lib/easy/palindrome_number.dart)                     |
+| 26. Remove Duplicates from Sorted Array     | [Link](https://leetcode.com/problems/remove-duplicates-from-sorted-array/)   | [Link](./lib/easy/remove_duplicates_from_sorted_array.dart)   |
+| 136. Single Number                          | [Link](https://leetcode.com/problems/single-number/)                         | [Link](./lib/easy/single_number.dart)                         |
+| 144. Binary Tree Preorder Traversal         | [Link](https://leetcode.com/problems/binary-tree-preorder-traversal/)        | [Link](./lib/easy/binary_tree_preorder_traversal.dart)        |
+| 169. Majority Element                       | [Link](https://leetcode.com/problems/majority-element/)                      | [Link](./lib/easy/majority_element.dart)                      |
+| 217. Contains Duplicate                     | [Link](https://leetcode.com/problems/contains-duplicate/)                    | [Link](./lib/easy/contains_duplicate.dart)                    |
+| 226. Invert Binary Tree                     | [Link](https://leetcode.com/problems/invert-binary-tree/)                    | [Link](./lib/easy/invert_binary_tree.dart)                    |
+| 342. Power of Four                          | [Link](https://leetcode.com/problems/power-of-four/)                         | [Link](./lib/easy/power_of_four.dart)                         |
+| 414. Third Maximum Number                   | [Link](https://leetcode.com/problems/third-maximum-number/)                  | [Link](./lib/easy/third_maximum_number.dart)                  |
+| 796. Rotate String                          | [Link](https://leetcode.com/problems/rotate-string/)                         | [Link](./lib/easy/rotate_string.dart)                         |
+| 944. Delete Columns to Make Sorted          | [Link](https://leetcode.com/problems/delete-columns-to-make-sorted/)         | [Link](./lib/easy/delete_columns_to_make_sorted.dart)         |
+| 2119. A Number After a Double Reversal      | [Link](https://leetcode.com/problems/a-number-after-a-double-reversal/)      | [Link](./lib/easy/third_maximum_number.dart)                  |
+| 2239. Find Closest Number to Zero           | [Link](https://leetcode.com/problems/find-closest-number-to-zero/)           | [Link](./lib/easy/find_closest_number_to_zero.dart)           |
+| 2481. Minimum Cuts to Divide a Circle       | [Link](https://leetcode.com/problems/minimum-cuts-to-divide-a-circle/)       | [Link](./lib/easy/minimum_cuts_to_divide_a_circle.dart)       |
+| 2490. Circular Sentence                     | [Link](https://leetcode.com/problems/circular-sentence/)                     | [Link](./lib/easy/circular_sentence.dart)                     |
+| 2520. Count the Digits That Divide a Number | [Link](https://leetcode.com/problems/count-the-digits-that-divide-a-number/) | [Link](./lib/easy/count_the_digits_that_divide_a_number.dart) |
 | 2544. Alternating Digit Sum             | [Link](https://leetcode.com/problems/alternating-digit-sum/)               | [Link](./lib/easy/alternating_digit_sum.dart)               |
 
 ## Medium

lib/easy/count_the_digits_that_divide_a_number.dart

@@ -0,0 +1,14 @@
+class Solution {
+  int countDigits(int num) {
+    var original = num;
+    var result = 0;
+    while (num != 0) {
+      var digit = num % 10;
+      if (original % digit == 0) {
+        result++;
+      }
+      num = num ~/ 10;
+    }
+    return result;
+  }
+}

test/easy/count_the_digits_that_divide_a_number_test.dart

@@ -0,0 +1,14 @@
+import 'package:leetcode_dart/easy/count_the_digits_that_divide_a_number.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group(
+    'Example tests',
+    () {
+      final ctdtdan = Solution();
+      test('1', () => expect(1, ctdtdan.countDigits(7)));
+      test('2', () => expect(2, ctdtdan.countDigits(121)));
+      test('4', () => expect(4, ctdtdan.countDigits(1248)));
+    },
+  );
+}