s.erase()
s.erase() // **Erases whole string**
s.erase(idx) // **Erases all characters after idx**
s.erase(idx, k) // Erases k characters after idx**
s.erase(itr) // **Erases character at itr** s.erase(s.begin() + 4);
s.erase(first, last) // **Erases character in range [first, last)**
1209. Remove All Adjacent Duplicates in String II Bloomberg VO
accumulate
int sum = accumulate(first, last, 0);
upperbound lowerbound
lower_bound(vec.begin(), vec.end(), target);
upper_bound(vec.begin(), vec.end(), target);
