solves is subsequence in python

Author: anishLearnsToCode

Diff for: README.md

@@ -105,7 +105,7 @@
 | 383 | [Ransom Note](https://leetcode.com/problems/ransom-note) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/RansomNote.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/ransom_note.py) |
 | 387 | [First Unique Character in String](https://leetcode.com/problems/first-unique-character-in-a-string) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/FirstUniqueCharacter.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/first_unique_character_in_string.py) |
 | 389 | [Find the Difference](https://leetcode.com/problems/find-the-difference) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/FindTheDifference.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/find_the_difference.py) |
-| 392 | [Is Subsequence](https://leetcode.com/problems/is-subsequence) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/IsSubsequence.java) |
+| 392 | [Is Subsequence](https://leetcode.com/problems/is-subsequence) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/IsSubsequence.java) [![Python](https://img.icons8.com/color/35/000000/python.png)](python/is_subsequence.py) |
 | 401 | [Binary Watch](https://leetcode.com/problems/binary-watch) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/BinaryWatch.java) |
 | 404 | [Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/SumOfLeftLeaves.java) |
 | 405 | [Convert a Number to Hexadecimal](https://leetcode.com/problems/convert-a-number-to-hexadecimal) | Easy | [![Java](https://img.icons8.com/color/40/000000/java-coffee-cup-logo.png)](https://github.com/anishLearnsToCode/leetcode-algorithms/blob/master/src/ConvertNumberToHexadecimal.java) |

Diff for: python/find_the_difference.py

@@ -1,17 +1,6 @@
-from typing import Dict
-
-
 class Solution:
-    def get_character_frequency(self, string: str) -> Dict[str, int]:
-        frequency = {}
-        for character in string:
-            frequency[character] = frequency.get(character, 0) + 1
-        return frequency
+    def ascii_sum(self, string: str) -> int:
+        return sum(ord(character) for character in string)
 
     def findTheDifference(self, s: str, t: str) -> str:
-        characters_s = self.get_character_frequency(s)
-        for character in t:
-            if characters_s.get(character, 0) == 0:
-                return character
-            else:
-                characters_s[character] -= 1
+        return chr(self.ascii_sum(t) - self.ascii_sum(s))

Diff for: python/is_subsequence.py

@@ -0,0 +1,8 @@
+class Solution:
+    def isSubsequence(self, s: str, t: str) -> bool:
+        i, j = 0, 0
+        while i < len(s) and j < len(t):
+            if s[i] == t[j]:
+                i += 1
+            j += 1
+        return i == len(s)