Adding 4 Java questions from Leetcode

[mohitsaxenaknoldus]

[vinayakj592]

Hi . Can you assign me this issue ?

[mohitsaxenaknoldus]

@vinayakj592 This is the issue that I opened for my PR. You can find the main issue in the issues list.

[Nitesh-thapliyal]

Hi . Can you assign me this issue ?

yes you can work on this issue

[Siddhesh4501]

can you assign me this issue

[adityamangal1]

can you assign me this issue

Assigned

[AnujSaha0111]

Can you please assign it to me? I want to work on it