Manish Dait

Added Stack implementation.

2

**PR Checklist:** - [x] My submission is formatted according to the guidelines in the [contributing guide](https://github.com/MakeContributions/DSA#contribution-guidelines) - [x] My addition is on refer on the language README.md file - [x]...

Fix some errors in java code.

1

**PR Checklist:** - [X] My submission is formatted according to the guidelines in the [contributing guide](https://github.com/MakeContributions/DSA#contribution-guidelines) - [X] My addition is on refer on the language README.md file - [X]...