Create 0535-encode-and-decode-tinyurl.kt

Author: a93a

kotlin/0535-encode-and-decode-tinyurl.kt

@@ -0,0 +1,35 @@
+class Codec() {
+
+    //to shorten URL
+    val encodeMap = HashMap<String, String>()
+    //to unshorten URL
+    val decodeMap = HashMap<String, String>()
+    val encodeCharacters = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    val tinyUrl = "http://tinyurl.com/"
+
+    // Encodes a URL to a shortened URL.
+    fun encode(longUrl: String): String {
+        if(longUrl in encodeMap) return encodeMap[longUrl]!!
+        var fakeHashCode = ""
+        repeat(6) {
+            fakeHashCode += encodeCharacters.random()
+        }
+        val encodedLongUrl = "${tinyUrl}${fakeHashCode}"
+        encodeMap[longUrl] = encodedLongUrl
+        decodeMap[encodedLongUrl] = longUrl
+        return encodedLongUrl
+    }
+
+    // Decodes a shortened URL to its original URL.
+    fun decode(shortUrl: String): String {
+        //since we are guaranteed that the shortUrl has been encoded
+        return decodeMap[shortUrl]!!
+    }
+}
+
+/**
+ * Your Codec object will be instantiated and called as such:
+ * var obj = Codec()
+ * var url = obj.encode(longUrl)
+ * var ans = obj.decode(url)
+ */