set.erase(iterator) is O(1) while set.erase(value) is O(log set.size())

set.erase(value) == set.erase(set.find(value))

In your first submission(TLE) you are not using the multiset::erase(iterator) version but instead using the multiset::erase(val). Since you have derefernced the reverse iterator auto it = *values.rbegin();, it stores the value at the end of the multiset.

According to C++ Reference, the complexity of

1. multiset::erase(iterator) -> constant

2. multiset::erase(val) -> logarithmic in container size, plus linear in the number of elements removed.

Since the second version removes every occurence of the value(if present) present in the multiset.

And if you need to remove only 1 occurence of the multiple then you should use multiset::find(val) to get a iterator and then remove using the 1st version.

Bro, you're just copying map<int, ll> every time in dfs, it's pretty heavy, you know.

auto it = *values.rbegin(); it is not iterator it is value because pointer return value on using *; auto it = values.begin(); if use it, it run