URLParser | Topcoder Archive

Problem Statement

When a web client (like a browser) requests a particular web page, it typically replaces certain characters with escape sequences. For instance, spaces are replaced with "%20". Your task is to reverse this, replacing every escape sequence in the input with the character it represents. Each escape sequence is formatted as "%XX" where XX is the ASCII value of the escaped character in hexadecimal.

Definition

Class:: URLParser
Method:: parse
Parameters:: String
Returns:: String
Method signature:: String parse(String url)
(be sure your method is public)

Constraints

url will contain between 1 and 50 characters, inclusive.
Each '%' in the input will be followed by a hexadecimal value between 20 (hex) and 7E (letters will be uppercase).
Each character in the input will have ASCII value between 32 and 126, inclusive.

Examples

```
"http://www.%20%40%20%40%20.com/%25"
```
```
Returns: "http://www. @ @ .com/%"
```
"%20" is the escape sequence for ' ', while "%40" stands for '@' and "%25" stands for '%'.

"%20%21%22%23%24%25%26%27%28"

Returns: " !\"#$%&'("

"%48%65%6C%6C%6F%20%57%6F%72%6C%64%21"

Returns: "Hello World!"

```
"%2525"
```
```
Returns: "%25"
```

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