077 [C++]

[alphaWizard]

Fixes #16

• [x] Pull Request Title is of form Problem Number [Language].
• [x] This solution is prepared by me and not copied from anywhere else on the web.
• [x] I have added a BY:{Your Hackerrank username} copyright comment in my solution.
• [x] I have updated index.md file (In appropriate folder in the appropriate manner).
• [x] I understand that pull request will be closed if I failed to update it even once in a week.

[sirjan13]

Good Work.Closed #20 via #21