Longest streak of rising prices

Question

Given a series of closing prices, find the length of the longest stretch where each price is strictly greater than the one before it.

prices = [4, 5, 6, 3, 4], k = ignored
-> 3            # the run 4, 5, 6

Return the length of the longest strictly increasing run of consecutive prices. Aim for $O(n)$ .

Accepted Answer

Walk left to right, keeping a counter of the current rising run. Each time the price goes up, extend the run and update the best; otherwise the streak breaks and the run resets to 1 (the current element starts a fresh run of length one). Tracing [4, 5, 6, 3, 4]: the run grows to 3 at the 6, resets at 3, then reaches 2. The best is 3. Time O(n), space O(1). Watch the empty-list case (return 0) and note that "strictly" means equal consecutive prices break the run, swap for = if flat stretches should count. Takeaway. Many "longest run of a property" questions are a single linear pass with a runn…

Longest streak of rising prices

Your answer

More Coding questions