Dynamic Programming

Snap onsites reportedly carry at least one dynamic-programming question, and candidates name DP as the round they wish they had drilled harder. The problems themselves are not exotic. They come from the same medium-centered bank as everyone else: a Premium question, the buy-low-sell-high family, a Premium question, Climbing Stairs, the grid walks like a Premium question and Unique Paths. There is no Snap-only DP trick to memorize. The pressure is the format around it.

That format is a live HackerRank editor over Google Meet, where the code runs against cases and pseudocode does not pass. So a DP answer here is graded twice: once on whether the recurrence is right, and once on whether you got a working table executing quickly and then cleaned it up. Every one of these problems yields to the same four-step recipe. Name the state, write the recurrence, pin the base cases, fill in dependency order. Get those four on the page and the code is almost mechanical.