Merge pull request #1310 from UndeadSheep/master

新增 哈希表部分的 C#版

problems/0383.赎金信.md

@@ -363,5 +363,22 @@ impl Solution {
 }
 ```
 
+C#：
+```csharp
+public bool CanConstruct(string ransomNote, string magazine) {
+        if(ransomNote.Length > magazine.Length) return false;
+        int[] letters = new int[26]; 
+        foreach(char c in magazine){
+            letters[c-'a']++;
+        }
+        foreach(char c in ransomNote){
+            letters[c-'a']--;
+            if(letters[c-'a']<0){
+                return false;
+            }
+        }
+        return true;
+    }
+```
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