Hard DS&A Under Latency

Jump does not hand you a tidy medium off a public list. The hard algorithm round uses problems that read like ordinary graph or dynamic-programming questions. Then you look at the constraints. A hundred thousand price levels, a billion allowed trades, a link graph too dense to walk by hand. The obvious solution is usually correct. It just does not finish inside the hidden time limit, and a solution that times out is a rejection, not a near miss. The whole round is a test of whether you reach the right complexity before you start typing.

That framing is what makes these problems specifically Jump rather than a generic screen. A firm whose edge is latency doesn't care that your code eventually produces the answer. It wants to see you spot the quadratic trap and pick the amortized-linear structure. It also wants the integer overflow and the empty input handled without a reminder. The three problems below follow archetypes that recur in the assessment: a monotonic-stack scan, a hop-capped shortest path, and a bounded-count DP. Each is posed in the market terms Jump tends to use, and each is tuned so the lazy approach loses.