added soln

[Swapna804]

Related Issue

• Info about the related issue

Closes: #[issue number that will be closed through this PR]
#283

Describe the changes you've made

Give a clear description what modifications you have made
Added solution soded in c++

Mention any unusual behaviour of your code (Write NA if not)

Any unusual behaviour of your code
NA

Checklist:

(To mark, write x inside the square brackets like this: [x])

• [x ] My code follows the guidelines of this project.
• [ x] I have performed a self-review of my own code.
• [ x] I have commented my code, particularly whereever it was hard to understand.
• [ x] My changes generate no new warnings.

Additional Info (optional)

Any additional information you want to give

[kanak22]

Add comments in your code and rename the codefile as

Best Time To Buy and Sell Stock.cpp

[kanak22]

Add comments in the code and rename the codefile exactly as the folder