XML Validation

When given an XML input file, this program will accurately validate if opening/closing tags are matched and closed in the right order.

When valid, the program will output "Valid" and a table of each tag used in the XML file with its frequency. The program will output "Not Valid", when it detects a tag mismatch, an unclosed tag or an unopened closing tag.

Example 1

Input

<book id="bk101">
      <author>Laakmann McDowell, Gayle</author>
      <title>Cracking The Coding Interview</title>
      <genre>Technical</genre>
      <price>44.95</price>
      <publish_date>2015-07-01</publish_date>
      <description>Basically the bible for technical interviews</description>
   </book>
<book id="bk102">
      <author>Frost, Jack</author>
      <title>It's Cold</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>It's cold outside and I wrote a book about it</description>
</book>

Output

Valid
book: 2
author: 2
title: 2
genre: 2
price: 2
publish_date: 2
description: 2

Example 2

Input

<abc>
  <def>This Tag is closed correctly!</def>
  <ghi>This isn't!</def>
</abc>

Output

NOT Valid