feat: add solution to lc problem: No. 0395

[pranay999000]

No description provided.

[yanglbme]

Hi @pranay999000 , I'll review the pull request within 24 hours. Thanks.

[yanglbme]

Thanks for your contribution. I'll format your code before merging into main branch. @pranay999000

[yanglbme]

if (counter.containsKey(r))
    counter.put(r, counter.get(r) + 1);
else
    counter.put(r, 1);

if (counter.containsKey(l))
    counter.put(l, counter.get(l) - 1);
else
    counter.put(l, 1);

we can use getOrDeault() in map, e.g.

counter.put(r, counter.getOrDefault(r, 0) + 1);

counter.put(l, counter.getOrDefault(l, 2) - 1);