D. J.:

- Added the leetcode problem and solution for 242 Valid Anagram

Author: nobodyPerfecZ

README.md

@@ -16,6 +16,7 @@ This repository contains awesome LeetCode problems and solutions written in Pyth
 - [169 Majority Element](https://leetcode.com/problems/majority-element/description/)
 - [189 Rotate Array](https://leetcode.com/problems/rotate-array/description/)
 - [205 Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/description/)
+- [242 Valid Anagram](https://leetcode.com/problems/valid-anagram/description/)
 - [290 Word Pattern](https://leetcode.com/problems/word-pattern/description/)
 - [383 Ransom Note](https://leetcode.com/problems/ransom-note/description/)
 - [392 Is Subsequence](https://leetcode.com/problems/is-subsequence/description/)

awesome_python_leetcode/_242_valid_anagram.py

@@ -0,0 +1,31 @@
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        """
+        Given two strings s and t, return true if t is an anagram of s, and false otherwise.
+
+        An anagram is a word or phrase formed by rearranging the letters of a different word
+        or phrase, using all the original letters exactly once.
+        """
+        if len(s) != len(t):
+            return False
+
+        counter_s, counter_t = {}, {}
+        for s_, t_ in zip(s, t):
+            if s_ not in counter_s:
+                counter_s[s_] = 1
+            else:
+                counter_s[s_] += 1
+
+            if t_ not in counter_t:
+                counter_t[t_] = 1
+            else:
+                counter_t[t_] += 1
+
+        for k_s, k_t in zip(counter_s, counter_t):
+            if k_s not in counter_t:
+                return False
+            if k_t not in counter_s:
+                return False
+            if counter_s[k_s] != counter_t[k_s] or counter_s[k_t] != counter_t[k_t]:
+                return False
+        return True

tests/test_242_valid_anagram.py

@@ -0,0 +1,12 @@
+import pytest
+
+from awesome_python_leetcode._242_valid_anagram import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["s", "t", "expected"],
+    argvalues=[("anagram", "nagaram", True), ("rat", "car", False)],
+)
+def test_func(s: str, t: str, expected: bool):
+    is_anagram = Solution().isAnagram(s, t)
+    assert is_anagram == expected