Expected Value Recursion Interview Questions
Expected value recursion interview prep for state values, first-step equations, boundary conditions, repeated games, and stopping-time mistakes.
Candidates practicing repeated games, stopping times, and Markov-style EV prompts.
State value idea
Expected value recursion assigns a value to each state, then relates that value to the expected values of next states.
First-step equation
Condition on the next move, roll, draw, or decision. The current value is immediate payoff plus expected remaining value.
Concrete example
In a toy reroll game, the value before rolling can be written as the average of either keeping each roll or moving to a reroll state.
Boundary conditions
Terminal states anchor the recursion. If the game ends with a fixed payoff, that payoff is the state value.
When recursion is worth it
Use recursion when the same structure repeats. For one-step games, direct expected value is usually simpler.
Common mistakes
Candidates often forget immediate reward or stopping cost in the recurrence. Write current payoff and future value separately.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.