[LEET-535] add 535

fishercoder1534 · fishercoder1534 · commit ae3fe1539249 · 2017-03-04T11:19:02.000-08:00
diff --git a/leetcode-algorithms/README.md b/leetcode-algorithms/README.md
@@ -3,6 +3,7 @@
 ## Algorithms
 |  #  |      Title     |   Solutions   | Time          | Space         | Difficulty  | Tag          | Notes
 |-----|----------------|---------------|---------------|---------------|-------------|--------------|-----
+|535|[Encode and Decode TinyURL](https://leetcode.com/problems/encode-and-decode-tinyurl/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/EncodeandDecodeTinyURL.java) | O(1) |O(n) | Medium | Design
 |530|[Minimum Absolute Difference in BST](https://leetcode.com/problems/minimum-absolute-difference-in-bst/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/MinimumAbsoluteDifferenceinBST.java) | O(n) |O(n) | Easy| DFS
 |529|[Minesweeper](https://leetcode.com/problems/minesweeper/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/Minesweeper.java) | O(m*n) |O(k) | Medium | BFS
 |520|[Detect Capital](https://leetcode.com/problems/detect-capital/)|[Solution](../../master/leetcode-algorithms/src/main/java/com/stevesun/solutions/DetectCapital.java) | O(n) |O(1) | Easy| 
diff --git a/leetcode-algorithms/src/main/java/com/stevesun/solutions/EncodeandDecodeTinyURL.java b/leetcode-algorithms/src/main/java/com/stevesun/solutions/EncodeandDecodeTinyURL.java
@@ -0,0 +1,32 @@
+package com.stevesun.solutions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * TinyURL is a URL shortening service where you enter a URL such as https://leetcode.com/problems/design-tinyurl and it returns a short URL such as http://tinyurl.com/4e9iAk.
+
+ Design the encode and decode methods for the TinyURL service. There is no restriction on how your encode/decode algorithm should work. You just need to ensure that a URL can be encoded to a tiny URL and the tiny URL can be decoded to the original URL.
+
+ Note: Do not use class member/global/static variables to store states. Your encode and decode algorithms should be stateless.
+ */
+public class EncodeandDecodeTinyURL {
+    public class Codec {
+        Map<String, Long> map = new HashMap<>();
+        Long maxValue = 0L;
+        Map<Long, String> reverseMap = new HashMap<>();
+
+        // Encodes a URL to a shortened URL.
+        public String encode(String longUrl) {
+            maxValue++;
+            map.put(longUrl, maxValue);
+            reverseMap.put(maxValue, longUrl);
+            return String.valueOf(maxValue);
+        }
+
+        // Decodes a shortened URL to its original URL.
+        public String decode(String shortUrl) {
+            return String.valueOf(reverseMap.get(Long.valueOf(shortUrl)));
+        }
+    }
+}
