pass problem 49 - group anagrams

Author: Bota5ky

hash_table/group_anagrams/Solution.java

@@ -0,0 +1,41 @@
+package hash_table.group_anagrams;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+
+/**
+ * @author Bota5ky
+ * @link <a href="https://leetcode.cn/problems/group-anagrams/">49. 字母异位词分组</a>
+ * @since 2023-11-03 18:56
+ */
+class Solution {
+    public List<List<String>> groupAnagrams(String[] strs) {
+        var map = new HashMap<String, ArrayList<String>>();
+        for (String str : strs) {
+            var key = generateKey(str);
+            var list = map.getOrDefault(key, new ArrayList<>());
+            list.add(str);
+            map.put(key, list);
+        }
+        var res = new ArrayList<List<String>>();
+        map.forEach((k,v) -> res.add(v));
+        return res;
+    }
+
+    private String generateKey(String str) {
+        var chars = new int[26];
+        for (int i = 0; i < str.length(); i++) {
+            chars[str.charAt(i) - 'a']++;
+        }
+        var sb = new StringBuilder();
+        for (int i = 0; i < chars.length; i++) {
+            int count = chars[i];
+            if (count > 0) {
+                sb.append('a' + i);
+                sb.append(count);
+            }
+        }
+        return sb.toString();
+    }
+}