added "392. Is Subsequence"

Author: fluttermiddlepodcast

README.md

@@ -17,6 +17,7 @@ Solutions from [LeetCode](https://leetcode.com) on 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)                         |
+| 392. Is Subsequence                         | [Link](https://leetcode.com/problems/is-subsequence/)                        | [Link](./lib/easy/is_subsequence.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)         |

lib/easy/is_subsequence.dart

@@ -0,0 +1,13 @@
+class Solution {
+  bool isSubsequence(String s, String t) {
+    var sP = 0;
+    var tP = 0;
+    while (sP != s.length && tP != t.length) {
+      if (s[sP] == t[tP]) {
+        sP++;
+      }
+      tP++;
+    }
+    return sP == s.length;
+  }
+}

test/easy/is_subsequence_test.dart

@@ -0,0 +1,13 @@
+import 'package:leetcode_dart/easy/is_subsequence.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group(
+    'Example tests',
+    () {
+      final isSub = Solution();
+      test('true', () => isSub.isSubsequence('abc', 'ahbgdc'));
+      test('false', () => isSub.isSubsequence('axc', 'ahbgdc'));
+    },
+  );
+}