Print all Nodes that don't have sibling in C++

[Striver404]

All nodes that don't have sibling

PR CHECKLIST

• My submission is formatted according to the guideline in the [contributing guide]
  (https://github.com/MakeContributions/DSA/blob/c63a39519a53f9e42487093f68507ba167569e3a/CONTRIBUTING.md)
• My addition is on refer on the language README.md file
• My addition does not have any spelling mistakes.
• My submission is a proper and friendly code lines.
• My submission has sample input-output of the program (NOT FOR PYTHON)

What kind of change does this PR introduce ?

• Bugfix
• New Algorithm
• Optimization in previous algorithms
• Code style update.
• Refractor
• Other, please describe:

Describe the PR:
This PR will add new algorithm in cpp(C++) to print all the nodes that don't have sibling.
Please consider this PR under Hacktoberfest 2022.

[welcome]

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[ming-tsai]

Hi @Striver404,
We are not participating in the hacktoberfest 2022, for more information please see #968, let me know if you are going to work on this or not.