How did things work before Flexible Mode?
Before Flexible Mode, every week a new exercise problem would be assigned to your account each Monday (at 7am Pacific Time). An email containing the full text of the problem statement would be sent at that time.
Each Wednesday every week the solutions for the new exercise would be revealed automatically. The full solution walk-through would be emailed at that time as well.
If you don't like the chosen exercise, you can chose to skip it but you can't remove it from your account or get another exercise instead. Once the exercise has been assigned to your account, it's there to stay.
How does Flexible Mode work?
With Flexible Mode enabled, every week an exercise credit will be added to your account (at 7am Pacific Time). An email will also be sent at that time with a recommendation for which exercise to solve next. The recommendation email will be one of the next 3 exercises in your chosen skill level.
From the recommendation email you can click through to preview the exercise. This shows the beginning of the exercise text, which should give you an idea of what the exercise is about. If you choose to solve the exercise, one exercise credit will be used and the exercise will be assigned to your account. If you decide you'd rather skip the exercise, you can select a different exercise from the Exercise Vault page (see the next question below).
You will no longer receive solution emails. Instead, once you're done solving an exercise that's been assigned to your account you can choose to lock-in your solution and receive a score.
How does the Exercise Vault page work?
On the Exercise Vault page you'll see the next 3 exercises in your skill level as well as the next 3 exercises in each other skill level.
Whenever you assign an exercise to your account, it'll disappear from the vault and a new exercise will appear from the same skill level. Whenever you skip an exercise, the exercise will stay in the vault and a new one will appear as well.
What does locking-in a solution mean?
When you lock-in your exercise assignment, you won't be able to modify your highest scoring solution anymore. You will still be able to submit new solutions, but the score your received (based on whether you solved the base problem or any bonuses) will not change after you've revealed solutions.
What happens if I don't use my exercise credit each week?
If you don't use your exercise credit, it'll stay in your account and you'll continue to accumulate a new credit each week. Exercise credits do not expire. You can find more details about exercise credits on the Exercise Credits help page.
If you have one or more exercise credits in your account, you can navigate to the Exercise Vault page and choose another exercise to solve with your exercise credits at any time.
If you don't choose to either skip or solve an exercise, you'll receive a recommendation for the same exercise for a few weeks in a row.
How does Flexible Mode on the Lite plan?
If you're on the Lite plan, Flexible Mode works the same way except that you'll receive a new exercise credit and an email recommending your next exercise each month rather than each week.
How can I disable Flexible Mode?
You can disable Flexible Mode from your preferences page. Visit that page, uncheck the checkbox, and click "Update":