DSA Studio

Advanced Data Structures Checkpoint

Trace trie terminal flags, Fenwick stored intervals, query/update walks, and repeated point assignments. Select one option per multiple-choice question.

Get every question correct to pass this checkpoint. You can review feedback, revise your answers, and submit again.

1. A trie contains only "planet". What do Search("plan") and StartsWith("plan") return? Select one answer.

Select one answer.

2. After inserting "bead", the trie inserts "be" twice. Which state is correct? Select one answer.

Select one answer.

3. For a one-based Fenwick tree, which internal interval does bit[12] store? Select one answer.

Select one answer.

4. F(13) sums the first 13 external values. Which internal cells does its Fenwick query add? Select one answer.

Select one answer.

5. For nums=[2,7,1,8,2,8,1,8], assign zero-based index 5 to 3, then assign it to 3 again. What is the inclusive sum over [2,6]? Enter one integer.
6. A length-8 Fenwick tree receives Update(2,-1), with external indices starting at zero. Which tree cells can change? Select one answer.

Select one answer.

7. F(k) is the sum of the first k elements, with F(0)=0. Which expression returns the inclusive external range [3,6]? Select one answer.

Select one answer.

8. A Fenwick assignment correctly propagates val-old[index] but never updates old[index]. Why can a later assignment fail? Select one answer.

Select one answer.

Join Discord