2023-02-08 update: added "69. Sqrt(x)"

Author: fartem

README.md

@@ -25,3 +25,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 58. Length of Last Word    | [Link](https://leetcode.com/problems/length-of-last-word/)    | [Link](./lib/easy/length_of_last_word.dart)    |
 | 66. Plus One               | [Link](https://leetcode.com/problems/plus-one/)               | [Link](./lib/easy/plus_one.dart)               |
 | 67. Add Binary             | [Link](https://leetcode.com/problems/add-binary/)             | [Link](./lib/easy/add_binary.dart)             |
+| 69. Sqrt(x)                | [Link](https://leetcode.com/problems/sqrtx/)                  | [Link](./lib/easy/sqrt_x.dart)                 |

lib/easy/sqrt_x.dart

@@ -0,0 +1,8 @@
+import 'dart:math';
+
+// https://leetcode.com/problems/sqrtx/
+class Solution {
+  int mySqrt(int x) {
+    return sqrt(x).toInt();
+  }
+}

test/easy/sqrt_x_test.dart

@@ -0,0 +1,13 @@
+import 'package:leetcode_dart/easy/sqrt_x.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group(
+    'Example tests',
+    () {
+      final sx = Solution();
+      test('2', () => expect(2, sx.mySqrt(4)));
+      test('2', () => expect(2, sx.mySqrt(8)));
+    },
+  );
+}