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Html Parser

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Some info: HTML is a markup language, that is based on tags. There are many types of tags, for example, html, div, h1, h2.
Each type of tag has start <tagName> and end </tagName> notations, for example <div> and </div>.
This pair may hold text content or children tags:

<div>
  <h1>text</h1>
</div>

You may learn more on the wiki.

Task: Today you will create your own HTML parser! It should print the content for each pair of tags.

There are two rules for printing order:

  1. the same hierarchy level tags are processed left to right;

  2. if a tag has other tags as children, children should be processed first. If there are no children or all of them were processed already, the tag can be processed.

Let's see how it works and why:

1. First example input: <html>content</html>

Output: content

Explanation: There is a single pair of html tag, its content is "content".

2. More complicated input:

<html>
  <h1>content1</h1>
  <h2>content2</h2>
</html>

Output:

content1
content2
<h1>content1</h1><h2>content2</h2>

Explanation: There are 3 pairs of tags: html, h1 and h2. h1 and h2 are preferred by rule 2 because they are children of html.
h1 goes before h2 by rule 1.

3. And the hardest one so far regarding input:

<html>
  <h1>content1</h1>
  <div>
    <h2>content2</h2>
  </div>
</html>

Output:

content1
content2
<h2>content2</h2>
<h1>content1</h1><div><h2>content2</h2></div>

See this one's explanation in the hint, if needed.

Hint

There are 4 pairs of tags: html, h1, div, h2.

  • h1 and div precedes html by rule 2;

  • h1 precedes div by rule 1;

  • h2precedes div by rule 2.

Sample Input 1: 

<html><a>hello</a><h1><h4>nestedHello</h4><h3>nestedWorld</h3><h6><br>top</br></h6></h1><br>world</br></html>

Sample Output 1: 

hello
nestedHello
nestedWorld
top
<br>top</br>
<h4>nestedHello</h4><h3>nestedWorld</h3><h6><br>top</br></h6>
world
<a>hello</a><h1><h4>nestedHello</h4><h3>nestedWorld</h3><h6><br>top</br></h6></h1><br>world</br>
Write a program in Java 17
class Main {
public static void main(String[] args) {
// put your code here
}
}
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