Merge branch 'master' into master

problems/0242.有效的字母异位词.md

@@ -88,19 +88,19 @@ Java：
 ```java
 class Solution {
     public boolean isAnagram(String s, String t) {
-        int[] strMap = new int[123];
-        for (int i = 0; i < s.length(); i++) {
-            strMap[s.charAt(i) + 0]++;
-        }
 
-        for (int i = 0; i < t.length(); i++) {
-            strMap[t.charAt(i) + 0]--;
+        int[] record = new int[26];
+        for (char c : s.toCharArray()) {
+            record[c - 'a'] += 1;
         }
-
-        for (int i = 90; i < 123; i++) {
-            if (strMap[i] != 0) return false;
+        for (char c : t.toCharArray()) {
+            record[c - 'a'] -= 1;
+        }
+        for (int i : record) {
+            if (i != 0) {
+                return false;
+            }
         }
-
         return true;
     }
 }