Sliding Window Quiz — Quiz

Question 1Select all that apply

Which questions are typical sliding-window problems? (select all that apply)

Longest substring without repeating charactersMaximum sum of k consecutive elementsNumber of ways to climb stairsShortest path in a graph

Question 2

A fixed window of size k slides one step right. How is the new sum computed in O(1)?

Re-add all k elementsAdd the new element, subtract the one that leftMultiply the old sum by kSort the window

Question 3

What is the maximum sum of 3 consecutive elements in [2, 1, 5, 1, 3, 2]?

Question 4

What is the length of the longest substring without repeating characters in "abcabcbb"?

Question 5

In the variable-window template for a LONGEST valid window, when do you update the answer?

Before expanding the windowInside the shrinking loopAfter shrinking, once the window is valid againOnly at the very end

Question 6

What is the time complexity of the variable sliding window, even with the inner while loop?

O(n²)O(n)O(n log n)O(k·n)

Question 7

Why does a sum-based sliding window fail when the array contains negative numbers?

Growing the window can make the sum smaller, so "shrink when too big" stops being reliableNegative numbers cannot be stored in a windowThe window length becomes negativeIt doesn't fail — it works the same

Question 8

What is the length of the shortest subarray of [2, 3, 1, 2, 4, 3] with sum ≥ 7?