Sync LeetCode submission Runtime - 18 ms (39.42%), Memory - 22.1 MB (12.02%)

Author: jimit105

0049-group-anagrams/README.md

@@ -1,18 +1,38 @@
-<p>Given an array of strings <code>strs</code>, group <strong>the anagrams</strong> together. You can return the answer in <strong>any order</strong>.</p>
-
-<p>An <strong>Anagram</strong> is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.</p>
+<p>Given an array of strings <code>strs</code>, group the <span data-keyword="anagram">anagrams</span> together. You can return the answer in <strong>any order</strong>.</p>
 
 <p>&nbsp;</p>
 <p><strong class="example">Example 1:</strong></p>
-<pre><strong>Input:</strong> strs = ["eat","tea","tan","ate","nat","bat"]
-<strong>Output:</strong> [["bat"],["nat","tan"],["ate","eat","tea"]]
-</pre><p><strong class="example">Example 2:</strong></p>
-<pre><strong>Input:</strong> strs = [""]
-<strong>Output:</strong> [[""]]
-</pre><p><strong class="example">Example 3:</strong></p>
-<pre><strong>Input:</strong> strs = ["a"]
-<strong>Output:</strong> [["a"]]
-</pre>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">strs = [&quot;eat&quot;,&quot;tea&quot;,&quot;tan&quot;,&quot;ate&quot;,&quot;nat&quot;,&quot;bat&quot;]</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">[[&quot;bat&quot;],[&quot;nat&quot;,&quot;tan&quot;],[&quot;ate&quot;,&quot;eat&quot;,&quot;tea&quot;]]</span></p>
+
+<p><strong>Explanation:</strong></p>
+
+<ul>
+	<li>There is no string in strs that can be rearranged to form <code>&quot;bat&quot;</code>.</li>
+	<li>The strings <code>&quot;nat&quot;</code> and <code>&quot;tan&quot;</code> are anagrams as they can be rearranged to form each other.</li>
+	<li>The strings <code>&quot;ate&quot;</code>, <code>&quot;eat&quot;</code>, and <code>&quot;tea&quot;</code> are anagrams as they can be rearranged to form each other.</li>
+</ul>
+</div>
+
+<p><strong class="example">Example 2:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">strs = [&quot;&quot;]</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">[[&quot;&quot;]]</span></p>
+</div>
+
+<p><strong class="example">Example 3:</strong></p>
+
+<div class="example-block">
+<p><strong>Input:</strong> <span class="example-io">strs = [&quot;a&quot;]</span></p>
+
+<p><strong>Output:</strong> <span class="example-io">[[&quot;a&quot;]]</span></p>
+</div>
+
 <p>&nbsp;</p>
 <p><strong>Constraints:</strong></p>
 

0049-group-anagrams/solution.py

@@ -1,16 +1,19 @@
-# Approach 1 - Categorize by Sorted String
+# Approach 2 - Categorize by count
 
-# Time: O(n k log k), n = length of strs, k = max lenth of string in strs
-# Space: O(n*k)
+# Time: O(n * k), n = length of strs, k = max lenth of string in strs
+# Space: O(n * k)
 
 from collections import defaultdict
 
 class Solution:
     def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
-        hashmap = defaultdict(list)
-        
+        ans = defaultdict(list)
+
         for s in strs:
-            hashmap[tuple(sorted(s))].append(s)
-            
-        return hashmap.values()
+            count = [0] * 26
+            for c in s:
+                count[(ord(c) - ord('a'))] += 1
+            ans[tuple(count)].append(s)
+
+        return list(ans.values())